Any server machine makes its services available using numbered ports -- one for each service that is available on the server. For example, if a server machine is running a Web server and a file transfer protocol (FTP) server, the Web server would typically be available on port 80, and the FTP server would be available on port 21. Clients connect to a service at a specific IP address and on a specific port number.
Once a client has connected to a service on a particular port, it accesses the service using a specific protocol. Protocols are often text and simply describe how the client and server will have their conversation. Every Web server on the Internet conforms to the hypertext transfer protocol (HTTP). You can learn more about Internet servers, ports and protocols by reading How Web Servers Work.
Networks, routers, NAPs, ISPs, DNS and powerful servers all make the Internet possible. It is truly amazing when you realize that all this information is sent around the world in a matter of milliseconds! The components are extremely important in modern life -- without them, there would be no Internet. And without the Internet, life would be very different indeed for many of us.
For more information on the structure of the Internet and related topics, check out the links below.
Related Articles
- How Domain Name Servers Work
- How Bits and Bytes Work
- How Web Servers Work
- How Routers Work
- How Routing Algorithms Work
- How LAN Switches Work
- How Ethernet Works
- How CGI Scripts Work
- How Firewalls Work
- How Home Networking Works
- What are IP Classes?
- What is a packet?
- Where are all the Internet domain names registered and maintained?
- How does a T1 line work?
- Quiz Corner: WiFi Quiz
More Great Links
- NetworkComputing.com: All About IP Addresses
- BIND - the software that implements most name servers
- Domain name registries around the world
- WhatIs.com Internet Terms
- The Original HTTP as defined in 1991
