Internet Hosts

Internet Hosts

Internet HostsEach computer on the Internet is called a host computer or host. The computers on the Internet hosts

are now millions of Internet lines, and satellite connections. They include large mainframe computers, smaller minicomputers, and PCs. When your PC or Mac dials into an Internet account, your computer is an Internet host, too.

are connected by cables, phone

Internet Protocol (IP) Addresses

Each host computer on the Internet has a unique number, called its IP address. IP addresses are in the format xxx.xxx.xxx.xxx, where each xxx is a number from 0 to 255.

IP addresses identify the host computers, so that packets of information reach the correct computer. You may have to type IP addresses when you configure your computer for connection to the Internet.
If you connect to the Internet by using a dial-up account,  your Internet Service Provider (ISP) assigns your computer an IP address each time that you connect. This system enables your ISP to get along with fewer IP addresses, because it needs only enough IP addresses for the number of users who are connected simultaneously (as opposed to assigning a permanent IP address to each customer of the ISP). If you use a high-speed DSL or cable Internet account, you may have a static
(unchanging) IP address, or your ISP may assign you an address each time you connect. Static IP addresses get rarer year and usually cost extra

Computers on a local area network (LAN) usually have IP addresses that are reserved for use on LANs rather than on the Internet itself. These addresses are usually in the range 192.168.x.x or 169.254.x.x. A server on the LAN usually assigns them: the most common IP assignment server is called DHCP (Dynamic Host Configuration Protocol.