IP Address and Domain Name

  In order to access the Internet, all kinds of companies and individuals have to pay money to telecom corporations or Internet service providers. Beside, individuals have to use own personal computers. Similarly, Websites need servers, which are powerful computers, to store Web pages and run databases. In fact, the Internet just consists of low quality routers and cheap copper lines.

  In spite of this, Internet users have to visit Website correctly. Then, the IP address appears like telephone numbers to solve the problem. Each Website has to own a IP address like telephone number. Definitely, a Website has to rent it year by year. To prevent mixing with telephone numbers, the IP addresses are added three “.” in the middle. Note that the dial-up and ADSL are just telephone lines. 

  For individuals, they will be allocated IP addresses temporally. After disconnection with the Internet, the IP addresses will be allocated to other Internet users. The reason is that the amount of IPv4 addresses is quite limited. Individuals can only use them when they are being online.
They have similar function: People can reduce the work of memorizing many numbers.

  You may create a phone book to set the telephone numbers, if you are using a cell phone. You can give each phone number a name. Then, you can see the name on the screen instead of phone number when you call someone. Similarly, to prevent remembering many IP addresses, domain name servers are used. Domain name servers on the Internet, can return the IP addresses for browsers, if Internet users directly enter Web addresses in the address bars of browsers or click hyperlinks.