7.4.1. Services of the Internet

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Internet service providers (ISP - Internet Service Provider) companies or institutions (such as T-Com, Iskon or CARNet in Croatia, AT&T in US and MTNL in India), which satellite or optical connections with several major Internet node abroad (mainly in the direction of America and Europe) and the thus ensuring high capacity connection to the rest of the Internet world. However, practice has shown that it can barely follow the needs of the growing number of members of Internet communities. When selecting an ISP of significance is the number of services that it provides to its customers. All services provided by e-mail, but do not provide any service to FTP, newsgroups, renting space on the disc, certain program support and etc. CARNet allows for almost all university departments.

User from their computers at work or at home by joining the Internet can:


Services of Computer & Network System

 Comp To make computers communicate with each other within the network of any kind, should be on the computer and allow the network system services, in order to allow retrieval further described services. The computer operating system is designed to know how to use system services, but also to offer their services to the environment. The holder of any communication within the local network and outside the TCP / IP protocol. According to TCP / IP - OSI model major protocols of upper layers allow the use of certain services. The basis of all is the client-server architecture, then architecture in which part of the network resource offers individual services and the resources that they use.

As for computer use is the most important service within the local network, as well as SOHO network, SHARING (AVAILABILITY) of devices connected to computer (like a printer), and directories and files of computer (such as multimedia content) to other participants in the network - File and Printer Sharing service. And the computer could fetch a resource on the Internet the most important service is the the DNS and DHCP obtain by server in the local network or SOHO device. By using first service enables to recognize the computer in the network by a domain name rather than IP addresses and vice versa, and the other service provides automatic assign of TCP / IP settings regarding computer to enable communication. All other services are these further upgrade on them, and follows a description of some of them.


WWW (World Wide Web)

 www The latest is an information service on the Internet. After the advent of the 1993rd The present multi-tens of millions of web pages is a synonym for the Internet. The first two words 'World Wide' mean global distribution, and the last word 'Web' means in this context of network computing. Scope of diverse content on the WWW servers is constantly growing. Almost everything can be found. Since the purchase of the product, technical support, advice, research papers, advertisements, price lists and who knows what all, depending on the site designated for and inspiration of their creator. So there are useful and useless, beautiful and ugly, organized and unorganized. Their development today is the extraordinary artistic and programming disciplines.

WWW is a graphical hypertext way of using the Internet using the HTTP protocol for transmitting Web pages and other information over the Internet, in principle, between the server and the user's computer. Web pages are written in HTML (Hypertext Markup Language) language, and recognizes them for this purpose designed browser (Internet Explorer, Firefox, ...). Service provides hypertext links between documents and combined display of text, images, sound and video, that enables the integration of different information content. Hypertext is a document or a system with related text units according to the principle shown in the following figure.

 Web-page links
Figure 7.4.4 Principle of linking web pages.

How certain region have specific graphemes, header website states the code page used records that follow. But that will not be relevant if your OS in, e.g. Africa does not have the character set used in Europe. Unicode will greatly increase the user-friendliness of reading web content regarding the diversity of languages and countries. Web pages are usually placed servers that allow other Internet services like email and the like. The servers are in operation almost continuously, and each of them has its own unique address, a URL (Uniform Resource Locator) and a single seat website content. One site address would be:

 'http://www.domain.hr/'              or
 'http://computer.domain.hr/'         or
 'http://×××.×××.×××.×××/'

Address is written on a hierarchically organized several DNS servers. 'http' protocol is a label, 'computer' is the name of the server or name of sub-domain. One can find and mark 'www' pointing to program support on the client side, which must be used to copy data (not necessarily). 'domain.hr' is a fundamental domain of the main domain in which the server and it stands true for all of the services that the server provides in its domain. It is possible to retrieve the desired content directly via the IP address (×××.×××.×××.×××), only need to know and remember. It's easier to remember domain name, especially if the name is associated with the desired content.

Tag 'hr' is an abbreviation for the state and each state is assigned a different label. It represents the main domain. But often, especially in the U.S., for the main domain tag to find com, edu, gov, int, mil, net, org, according to the type of content that is presented, and is planning to introduce some more.

Thus defined address of site is unique throughout the world. The award is called the basic and main domain local ISP decides in consultation with the customer along with relevant international association of leading Internet about taking care so that each of them is unique in the world (no two are the same). Label domain and main domain is an integral part of the labeling of other services offered by the server.

As the number of web pages is a huge phenomenon understandable growing number of WWW pages with type catalogs, which over the content or accountable to the inquiry, pointing to other web content. Those are web search engine that contain the tools to search different databases, documents, databases, e-mails, files, multimedia content, Web's, and more. This sought as 'Google' and 'Yahoo' really allow efficient browsing the Internet, but also require a detailed knowledge of the principles and rules with which they work. What you can not find the look you over 'Astalavista' required.


Electronic Mail (E-mail)

 e-mail Service which is much earlier than the World Wide Web and has won hearts of the users. The idea that in a few minutes you can deliver, text, image, audio or video recording of any person on the planet was unfeasible until recently, but now, thanks largely to the rapid expansion of the number of Internet users and the increasing speed of communication, was to become reality of business and social communication. Mainly used for the contents of up to 500 kB. Otherwise need to use the FTP service.

It is customary that the electronic address contains two parts separated by ' @ ' (<ALT> + <64>). The first part is usually the user selected a name, but it could be anything else, any term. The second part is the name of a specific electronic ISP or a local name from the list of network nodes that belong to its domain (DNS) server. For example, for CARNet applies:

 'name@domain.hr'

It is an abbreviated form for which the server CARNet 'name' is the code of the person, or the name of the application server - USER_NAME or USE_ID, behind which lies in content table with registered users in the system supporting server, real name and surname of the ID belongs. The actual e-mail address along with the user information and the name and location of the computer is:

 'Name.Surname@domain.hr'              or  
 'Name.Surname@computer.domain.hr'

T-Com Provider (ISP) for the city of Split in Croatia applies:

 'Name.Surname@st.t-com.hr'

So something extended address, where is 'T-Com' core domain and 'st' sub-domain, which indicates to the user is from the city of 'Split'. How are server systems are mainly based on a Unix-like operating systems, and almost all the members of the wide world of computer networks, the use of local graphemes in computer name and domain name is not recommended. Indeed, local graphemes are not recommended even when defining user_name, name and surname, nor in the messages to be sent as well as to and content of the message, because it is doubtful that some 'handle' interpret a server in America or Africa. So instead ČŽŠ.. should be used CZS.., basic ASCII characters. Local directories can contain local institution graphemes in the names because they have international significance, but not advisable.

The cost of sending electronic letters to any multimedia attachment to any Internet user, regardless of the distance is less secure than sending greetings for the New Year traditional postal services, particularly if it is sent through the mailing-list. Difficulties may arise if only the system administrator on the receiving side of the transmit or introduce restrictive measures in respect of defense against unwanted attachment types in an electronic letter for security needs.

In the business world, this type of communication is more prevalent. No more waiting on the phone or fax machine to free selection signal or a sign of nervousness on the calendar. This is irritating especially if the destination is no one to receive the message. Such a user sends a message to his partner, an electronic mailbox that this will sooner or later read and return the response.


News Groups

 News Service derived from e-mail, which allows the public debate on various issues. As part of this service, it is possible to follow the discussion on any topic or even start a new topic for discussion. Similar to the e-mail message is sent to all members of the group, and everyone signed on the group read the message and optionally answer them. Very practical and convenient to search for help in solving business problems.

 'news://news.domain.hr/'

Almost every Internet service provider offers this very interesting and useful features.


FTP (File Transfer Protocol)

 FTP Before the World Wide Web and FTP was the only way to transfer large files between computers of Internet users. Allows access to a computer on the Internet (if it's public or available to the password), preview content on its hard disk, finding the necessary files and copy on its own disk. This Internet service is not as simple as the World Wide Web, but it is very useful.

Using program support for FTP will set about establishing communication address is similar as in the previous examples:

 'ftp://ftp.domain.hr'              or
 'ftp://computer.domain.hr'         or
 'ftp://×××.×××.×××.×××'

File transfer function is increasingly taking the WWW, so that with a confirmation copy selected files as needed and the auxiliary program with WWW browser (GetRight or similar) which will take over the task of FTP transmission and after stop using the browser.


IRC (Internet Relay Chat)

 IRC This service allows the Internet to one or more of Internet users who are hooked to the same channel at the same time see the text that you type on your computer, and the texts of other active users typing on his computer. Channels to 'talk' to exist for almost all areas of interest. This system is much faster than e-mail because it is conducted almost simultaneously send and read messages, but it is much more expensive than e-mail, because it requires a long term connection with the Internet, but only for those who pay for this service out of his own pocket.


Telnet

 Telnet Internet service that allows the user logs on and runs on a remote computer and use programs installed on the remote computer. Of course, the remote computer must be enabled in the user access rights to the computer. For security reasons this service on many servers is not allowed. It is better to say that the Telnet 'Terminal Emulation' software support, which to communicate with a computer connected via a TCP / IP stack. Thus, the emulator work former unit called 'Terminal' (from the mainframe era). This same role today better performed by programs that use SSH (Secure Shell) connections over TCP / IP as the carrier of connection, but all traffic is encrypted. Although this mechanism provides plenty of security in the work with the server, system administrators are reluctant to make this service available to all users.


Voice / Video Communication - Skype

 Skype Internet networking service that allows users to voice / video communication. This implies that the devices that use this service have built-in camera and microphone. Although this service is usually used for that purpose, in addition to communicate written messages, internet calls, sharing information and much more. Can be used as a common telephone communications. This service is based on the free program support allows free calls to anyone who has installed a 'Skype' program support on his computer, anywhere in the world. Thanks to the high speed internet communication has increasingly better quality. Can be achieved over a fixed PTT communication lines or cell phones or send text messages at very reasonable prices, without any special setup or subscriptions.

It should be emphasized that this is no communication between user devices (phones), but between two user accounts registered on 'Skype' service which includes registration, enter the user_name and password protected some basic personal information. The user can later modify the information in their profiles as needed. 'Skype' has just developed that allows retrieval of user account and select the desired action and can be installed on a PC with Windows, Mac or Linux operating system, several kinds of mobile phones, and what is best to communicate between multiple users in a commercial version it's the conference using the 'Skype Manager' program support to be purchased. Provides for the use of TV sets in communication. So, a kind of free video phone, which offers even extra specific services. With this program support the new generation of smartphones and tablets, using the resources of the existing SOHO infrastructure, 'calling' becomes really cheap. This service should not be confused with VoIP (Voice over Internet Protocol) technology that allows the transmission of voice communications over Internet networks for the purpose of protocol design, that 'Skype' is used in the sense of some kind of Peer-to-Peer (P2P) communication.

Something similar is service 'Viber' that allows free calls, SMS and MMS share content with anyone, anywhere, but there is no ability to transfer video as 'Skype'. Similar to the above mentioned is service 'WhatsApp', multiple platform mobile application to send messages in real time.


Social networks

 FaceBook Social networks are a newer phenomenon and do not belong in a separate category because they contain almost all of the previously mentioned services, unified to work in an easy, friendly way. Not only does it allow communication among users but also represent a form of socializing. There are already quite developed FORUMS, bulletin boards web version, which uses a technology exchange text via the web site, or web sites. It is a debate on a topic initiated by a member of the forum. As a rule, seek enrollment, mostly for free, using the application type USER_NAME  / PASSWORD, typically associated with a user's address in the e-mail regarding the identification. To service the forum is not abused in any way and to respect the rules of acceptable behavior take care administrators - moderators appointed by the forum owner of the forum members themselves who usually takes this obligation voluntarily reported. These individuals may be excluded from membership and delete and delete malicious content, basically supervise. Depending on the number of members, topic, traffic, and the owner of the forum depends with how the server program to use the forums.

Purpose of writing by arbitrarily selected topics has a BLOG (contraction of the term 'web log'), a type of website that is usually maintained by an individual, is organized much like a personal diary with respect to input regarding the content of the description of an event or topic, with the possibility of enriching the content and graphics video. As a kind of diary of events, entered contests are usually displayed in reverse chronological order. Usually allows readers can add here your comments on the topic that is currently being processed..

One of the most popular is FACEBOOK, a social network where users can set up their image, disclose your personal information, describe their interests, publish their written and photographic pieces, develop some thematic discussions, etc. with the possibility that any of the members receive in 'his 'group or a member of it off. A sort of meeting place, so it is possible even to initiate effective political, protest, humanitarian or some other action. Has a similar purpose, and TWITTER, social networks and mikrobloging service, which uses instant messaging, SMS or web content. There are also 'LinkedIn', 'Myspace', 'Tumblr', 'Instagram' and the other, each with its own characteristics. What made them especially adorned with a tremendously rapid dissemination of information, and misinformation. Thus, the negative effects are possible.

 YouTube Very specific Internet service YOUTUBE. Used to exchange video content where users can upload, view and evaluate video, up to 'Full HD' resolution, respecting copyrights. It is forbidden to support pornography, violence, crime, embarrassment and defamation, and advertising. For your own protection YouTube reserves the right to use, modify and delete content posted. In summary, one can find all sorts of things, from useful to useless content, but also very funny and naughty and critical to everyday events. Whether it is a film and music videos covering YouTube to be a free medium for promoting a filmmaker, musician or politician and there have been cases where people have gained popularity in this way, and then accepted by traditional media such as newspapers, radio and television.

Essentially all of these are web applications that typically require enrollment to confirm the response to the e-mail messages to prospective members. Registration is usually type USER_NAME / PASSWORD or E-MAIL / PASSWORD, and the user alone chooses who will be his personal data are visible in your profile settings. But for one such network services server is usually insufficient. Caring for their functioning in particular computers-servers; datacenter. The forerunner of the above was certainly B.B.S. era of modem communications.


Search Engines

 Search Already these social networks to enable retrieval of content that is stored and monitored, but a special group of interconnected computer servers in a DATACENTER and interconnected datacenters in a unique system. The basic idea is that all registered facilities are located on one or more servers can be found in some sort of elaborate directory by interest groups (sports, music, movies ...). For this purpose, the contents should be reported to the owner who approves the inclusion of datacenter facilities and reported its index. Advanced way of this is that all of the reported content indexes and their keywords are ranked according to their relevance. Through a simple form to enter the desired search term on the basis of which offers all of the titles that describe the content of the list according to the achieved ranking. So, basically it is a huge database that is constantly updated.

Almost every state has its own internal search engine, but the most interesting are those international type as YAHOO!, GOOGLE and BING. Are listed in the order they occurred, although they appear to their versions that preceded them, today its possibilities are not even close. Course and apply them to the desired content complying with the prescribed rules. Basically all are oriented to search HTML text or the images, though some of their skills are recognized and other formats of documents and index them. Currently qualified as a browser web content considered GOOGLE. In addition to enabling the global search and local search free within declared site. Algorithm correspondence of new titles, indexing and ranking their content daily in construction, a mechanism for storing data and their storage is not reduced more on copying disks themselves but to each other constantly copying content themselves datacenter which has quite a few in the world, about forty. Seen from the perspective described something of very great importance should be kept by them.


Wikipedia

 Wiki A free encyclopedia built collaboratively using wiki software (Creative Commons Attribution-ShareAlike License). Wikipedia was founded in 2001 as a project for the construction of encyclopedia, which is accessed via the Internet (online), on the basis of free access and the creation of free content. Since then, it has grown into the largest encyclopedia ever created, which includes more than five million articles in the English language, and relies on the contribution of volunteers. Although Wikipedia has achieved incredible success, there remains a lot of work in progress. There are still large gaps in the coverage important themes with the appropriate articles. Many articles, even those vital, is not yet considered as high quality. It was established more than 200 editions in non-English languages, at the local level where most missing volunteers. There are still many inconsistencies and a lot of work that needs to be done about it.

Since articles generally not reviewed by the authorized institutions, it is very questionable how much can be written in trust, in particular as regards the historical events at the local level. Technical articles are mostly credible, but for other questionable credibility. Essentially useful service, but the desired content should always be carefully considered.


Web-Hosting (DATACENTER)

 Data Center No long that it is the development of technology, high-speed computers and Internet connections, provided that the user can purchase a server in a datacenter, who cares about the correctness of the service provider, and in which the user via FTP Service set up your web content (web hosting). Of course the service is paid, but in the age of virtualization computing platforms becoming cheaper and more accessible with very reasonable prices. What set the servers and as a server lease depends on the users. This requires the lease currently available domain names and site facilities in which servers become recognizable. 'IT Alphabet' uses just one of them and has been reported in the previously mentioned search engines. The basic difference with the search engines is that in these datacenter care about the content (data) leads users, the concern for the safety of equipment and access to available web content leading provider of these services. Impressive is the concept of 'Google container data center' that uses Google.

Electronic versions of NEWSPAPERS and PERIODICALS is also one of the most important services. Main service is not fully available, in addition to the subscription, which is often not expensive and allows access to archived editions. Similar is with the offer of books and multimedia content. In addition to this specialized sites (PORTAL) offers a variety of facilities, from the amendments set out TV content, educational facilities, entertainment facilities to the ××× content. The variety is so great that it is very difficult to share content in a few categories. The above is fundamentally changing habits of users, especially the growing popularity of tablets, which are becoming, for example, an free integral part of restaurants offering. With the morning coffee not to use a paper version of the newspaper rather than a tablet. From the above it is clear why the quality of the program for viewing Internet content (browser) is given more prominence.

 Cloud What has set up 'Google' with its 'Android' platform, and skillfully used 'Facebook' and others, and is the basis of working at recent 'Windows' operating systems - data storage in one location (OneDrive storage), more correctly data centers that are continuously interconnected copy and synchronize data and presented to the user as a single group - CLOUD, somewhere on the Internet, a trend that is increasingly spreading to enable the user to use their data anywhere and anytime, even with different platforms (PC, Tablet , Mobile ...). To preserve the privacy of the user traffic to the cloud must be encrypted, so if security required and the data itself is encrypted. On this principle, essentially functioning banks and public institutions that offer customers a variety of services; bill payment, payment processing, issuing various documents and the like.

 Free Lottery  Lotto As usual, the service should be paid, under the principle of 'How much money - so much music.', But the services that are beneficial to the general welfare generally are not charged. Membership in some places costs, especially those that contain pirated or ××× content. To get the best quality movies, and other video and music content has to be paid. Some of the games can be played free of charge online, but if you want to play efficient with others on the net, or for example a good tank armor - pay. Membership at gambling sites and the like is mostly free, but do not be fooled by the fact that you will earn some money there. But there are ways to earn something in a legitimate way like - a free lottery. For more information, see Chapter 7.7. Or simply click on the icon at the beginning of the paragraph.




SUMMARY:

Number of Internet services is continually growing and the most successful ones adorned efficiency (Internet banking) or any other specificity (FaceBook). There are an increasing number of seats offered by shopping (web shop) via Internet services, so that everything can be bought using Internet banking or specialized services (such as PayPal) to pay, and that goods ordered came to the house without the user having to visit the mighty stores. Does not have to be bought only through specialized firms sites. Sites like 'eBay' or 'Amazon Marketplace' offers customers around the world to present their products or articles for sale with a minimum fee. Of course there are also local shops similar listed as the site 'Njuškalo' (Sniffer) in Croatia.

Electric power consumption can be monitored by entering the electric meter readings. An increasing number of newspaper and television stations part of its content posted on their sites. The increasing speed of communication by enabling end user development just mentioned and similar services, and the author of these lines of thought is that society will effectively repose precisely on the quality of their own internet network and a variety of services over the Internet can provide. Of course, with the use of security protocols and mechanisms for the protection of users.

 WEB Browsers Thereby the most important role has software of WEB browser, and adherence to the recommendations, which are almost the standards of the W3C (World Wide Web Consortium) consortium. The World Wide Web Consortium (W3C) is an international community where Member organizations, a full-time staff, and the public work together to develop WEB standards. Almost all services available over the Internet are used particularly through WEB browser through which, by completing content offered various forms, leads to the desired results. Indeed, even devices (such as 'WD TV Live' or 'WD My Book Live') as an interface to configure using a WEB browser via a WEB-server blend in the their software. Basically all comes down to the user (client) via the browser which is used more or less interactive content on some Web page server. So, a typical client-server architecture.

Internet telephony services (VoIP - Voice over Internet Protocol) is becoming more frequent, as well as the transmission of TV pictures (IPTV - Internet Protocol TeleVision). Compared to the usual signal transfer for this type of communication over a dedicated communications channel, these services are based on the transfer of a huge number of individual data packets, as in essence it works and that users are coming up different paths to the destination, and read, and the information they carry 'made' the appropriate analog voice and TV signals. Especially true for TV content that's a huge amount of data, and stated is possible only because of the much higher speed and bandwidth of network devices lately. It is indisputable that the number of services on the Internet more and more and more varied. Therefore, it is subject to abuse and 'publish' the multitude of inaccurate data. Well not quite true that everything that is found on the Internet can be trusted. And who all of this may monitored?

What must not bypass the are more and more of services of major importance for society, both as school enrollment, electronic processing of certificates, registration exam students electronically, a growing presence in medical and pharmaceutical services, better information on the content of the pages of various ministries and the like. Economy and tourism services could be by means to be separate topic. Definitely, it is very diverse and useful services that surely have significance in the development of society. More and more contents type of e-this / e-that. One of the unusual service, for example, map of visits to the site as in the example on the search page, or globe of visits to the main page of the site (domain). Useful services is speed measurement of Internet access, which can be set to your own site or offers datacenter or Internet service provider (ISP).

Described the concept of parallel computing as mobile communication networks, which in addition to its basic dedicate - CONVERSATION, offers a more diverse services, from reading the geographical location to download games and music. Mobile device for its subject belongs to the Chapter 'Specific IT Concepts', especially as more and more becoming a 'small personal computers'.

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Citing this page:
Radic, Drago. " IT - Informatics Alphabet " Split-Croatia.
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