Inglese - Internet
Internet was created in the 1960s and it was funded by the US government.
it took many years for the internet to become popular around the world. Now internet has been a part of our daily lives.
To get connected, you need a computer, the right connection software and a modem connected to the phone line. You also need an account with an Internet Service Provider (ISP), which allow the pc to connect with the rest of the net.
Today ISP offer a broadband , high-speed connection. The most common type are cable and ADSL that works with the phone lines.
A modem coverts digital signals into analogue signals so that data can be transmitted across the cable network.
The protocol used for data transfer on the internet is known as TCP/IP, this is like the internet operating system. Every computer connected to the net, is identified by a IP address.
Networks are classified in:
Geographical area such as: PANs to laptop or mobile phone, LANs cover a building, MANs cover a campus or city and finally WANs cover a country or continent.
Architecture such as: client-server network where there are computer server that distributes information, and computer client that riceive this information. Then there is Peer-to-Peer network that the computers have the same capabilities.
Topology or layout: There are a Bus network where all the computer are connected to a main cable, Then there is a Star network where all computers are connected a central hub. Finally a Ring network, all computers are connected to one in another in a continuous loop.
Network protocol: This is the language that computers use to comunicate with each other. The internet, infact, uses TCP/IP.
There are many types of wirelss networks to connect the computer or phone on the Net. Examples are :
Satellites for long distances
WiMAX for connecting Wi-Fi hotspots
Wi-Fi for medium-range distances
Bluetooth fot short distances
GSM for mobile phones.