Many people understand sockets much better then they think. When you surf the web and go to a web site called www.altavista.com, you are actually directing your web browser to open a socket connection to the server called "www.altaviata.com" with port number 80. If the connection is successfully established then your web browser will report "Web Site found. Waiting for data". Your web browser then sends some information to the web server identifying the page that is being sought. The web server then sends the HTML for that page. Interestingly, if a page contains graphics, then the web browser establishes another socket connection for each graphic that is required.
Examples of software that are socket clients:
Examples of socket server software:
Some Well-Known port numbers: