5.2 THE INTERNET THE INTERNET AND ITS SERVICES The Internet is a global network of computer networks. The official date of its birth is 1st January 1983, when the protocol TCP/IP was established and different kinds of computers on different networks were able to communicate for the first time. However, the origin of the Internet goes back in time to 1969 and the first packet switching WAN called Arpanet (Advanced Research Project Agency Network), a network which involved the American Defense Department and some academic institutions. The most significant rise of the Internet in terms of the number of users was in 2000 and since then it has continued to increase steadily. What do you use the Internet for? Common examples of webbased emails are: Yahoo Mail, Gmail, Hotmail, etc. Common examples of email clients are Outlook, which is part of Microsoft Suite, and Thunderbolt, which comes with the Firefox browser. Internet connection In order to connect to the Internet, the following are needed: an Internet Service Provider, or ISP, such as Yahoo, Libero, Alice, etc., and a modem, which converts digital signals into analogue signals and vice versa. The modem calls and connects the device to the ISP and receives a temporary IP address which identifies the device on the Net and it is connected. However, the Internet is just a path that makes us reach the website we want to connect to. For this reason, the ISP sends the request, i.e. the name of the site we want to reach or URL, to a server called Domain Name Server, or DNS, which acts as a kind of directory. Once the request arrives, the server retrieves the website and sends the correct data to our computer. copper: rame cradle: supporto to get beamed: essere inviato sotto forma di raggio satellite dish: antenna parabolica domain type john.smith @ computer-world. co. uk country code user name 222 LINKING COMPUTERS at domain name or service provider Internet services The Internet offers different services that can be grouped in five broad categories: Communication; E-commerce; Leisure; Information retrieval; Education. Email While for other types of services we just have to access a website, using an email means having an address on the Internet from which we can send and receive messages. Electronic mail, or simply email, is a way of sending text-based messages and documents from one computer to another or from a WAP (Wireless Application Program) mobile phone or digital television. Emails can be: web-based , which means they are operated from a website which allows users to access their email accounts as long as they have an Internet connection. It is not necessary to be connected to a particular ISP and an email address can be got from any online computer in the world, but the messages are not downloaded into the host computer. To access the website, a login with a username and a password is required; sent and received via an email client , a software program that uses a clientserver architecture: emails are sent from many clients to a central server which then delivers the messages to the correct email addresses. The emails are stored on the host computer, they are accessible faster than using a web-based interface and can even be accessed offline, but cannot be accessed by other devices.