Currently the largest commercial online service, with approximately 15 million subscribers. For more information on AOL and other online services, see Part V.

America Online is an Internet Service Provider ( ISP), as well as a online service provider with its own web portal and community. AOL is owned by Time Warner, which uses the NYSE stock symbol "TWX". Today, America Online is perhaps best known for being a leading ISP during the Internet boom of the 1990s. AOL's main competitor is Microsoft's MSN. For more information, visit AOL web site. Abbreviation: AOL.

America Online is one of many Internet Service Providers and describes itself as an interactive service provider. AOL uses what is known as proxy servers to improve user response time. What this means is it searches its cache for a requested URL and if it has it stored, it returns it to the user. This often means you are not seeing the most recent version of that web page. It is recommended that AOL subscribers use a separate browser such as Netscape or Internet Explorer to access WebCT courses.