An Internet forum is a discussion area on a website. Website members can post discussions and read and respond to posts by other forum members. An Internet forum can be focused on nearly any subject and a sense of an online community, or virtual community, tends to develop among forum members.

An Internet forum is also called a message board, discussion group, bulletin board or web forum. However, it differs from a blog, the name for a web log, as a blog is usually written by one user and usually only allows for the responses of others to the blog material. An Internet forum usually allows all members to make posts and start new topics.

An Internet forum is also different from a chat room. Members in a chat room usually all chat or communicate at the same time, while members in an Internet forum post messages to be read by others whenever they happen to log on. Internet forums also tend to be more topic-focused than chat rooms.

Before a prospective member joins an Internet forum and makes posts to others, he or she is usually required to register. The prospective member must usually agree to follow certain online rules, sometimes called netiquette, such as to respect other members and refrain from using profanity. When a member is approved by the administrator or moderator of the Internet forum, the member usually chooses his or her own user name and password. Sometimes, a password is supplied. An avatar, or photograph or picture, supplied by the member can appear under the member's user name in each post.

The separate conversations in an Internet forum are called threads. Threads are made up of member-written posts. Internet forum members can usually edit their own posts, start new topics, post in their choice of threads and edit their profile. A profile usually lists optional information about each forum member such as the city they are located in and their interests.

An Internet forum administrator or monitor may also participate in the forum. A forum administrator can usually modify threads as well as move or delete threads if necessary. Administrators can also usually change software items in an Internet forum. Moderators often help the administrator and moderate Internet forum members to make sure the forum rules are being followed.

Internet forum software packages are written in many different program languages. Perl, PHP, ASP and Java are common programming languages used in Internet forums. Either text files or a data base can be used for the configuration and storage of posts in the forum.