HOW TO USE COMPUTER TO COMMUNICATE

Inside a computer network may communication programs are installed on intranet computer to connect to the internet or even to internal computers

Web Browser: A web browser is a client program to navigate the www and retrieve web pages. It runs directly on the user’s computer as a client and connects to external web-servers, identified with the www prefix in the internet name, to retrieve web pages.

Mail Reader: is a client program to send and retrieve emails. It runs directly on the user’s computer as a client and connects to a mail-server, a program in charge of collecting and dispatching emails.

Another way to read and send emails is through webmail systems, which are websites where the user can enter and read his received email and send new ones acting directly on the mail-server, without downloading them nor using any client. It can be useful for various reasons: it does not require the installation of mail reader program; old received email are always available on the website and can thus be accessed from home, office and while travelling, even without a personal laptop; the mailserver takes long email, which can be costly and in some situations, impossible and usually the email space is limited.

Voice Over IP Programs: VOIP programs are able to used the computer connection as a substitute for standard telephone. Equipped with either microphone or headphones or with a real telephone like device, the user can send his voice through the internet to remote computers or even to real remote telephones, thus saving on telephone bills.

VOIP requires a subscription to a VOIP’s website, the most famous being skype, who decides the telephone fares. Typically calling other VOIP’s user is free all over the world, while calling fixed telephones depends only on the destination country and is independent from the caller’s country, with a fare which is comparable to the standard local telephone call (about 2 cent/minute). On the other hands, calling mobile telephone is for the moment still very expensive (about 7 cent/minute); for this reason, special VOIP telephones, which can be programmed to automatically decide between VOIP and the standard local telephone line according to the dialed number, are appearing on the market.

A similar system is Whatsapp messaging system, in practice a “sms over IP” system in which people exchange messages and multimedia material through a chat system installed on mobile devices. The major diference with respect to most internet communication systems is that whatsapp uses a fully centralized architeure, i.e. all communications pass through whatsapp company servers and there is never a real direct communication between two users. However, non-technical users do no realize nor care about it and thanks to its very good usability it is quickly surpassing emails’ and sms exchanges.

Search Engines: A search Engine is special program running on a website which offers to the user the possibility of searching other websites for specific web pages. The user needs to connect to the search engine website and digit the keywords, or something even a complete question, and the website returns the list of relevant web pages.

Search engines use a crawler technique: they continuously go through the know web pages memorizing their content and trying to discover other web pages through the contained links. In this way they able to memorize most of the www’s pages (more than 9 billion pages), even though some not linked websites can remain unknown to search engines.

The most popular search engines are Google, Yahoo!, Bing.