A forum is essentially a website composed of a number of member-written threads. Each thread entails a discussion or conversation in the form of a series of member-written posts. These threads remain saved on the forum website for future reading indefinitely or until deletion by a moderator. However, forum software can be considerably more advanced.Most forum software allows more than one forum to be created. These forums are containers for threads started by the community. Depending on the permissions of community members as defined by the board's administrator, they can post replies to existing threads and start new threads as they wish.Forum software can be broadly divided between those which allow visitors to post anonymously, and those which attribute posts to a registered username.For username-based software, visitors register using a username and a password, and possibly an e-mail address for validation purposes. In these types of forums, the members are often able to customise both how their posts display to others (for example avatars, user profiles and signatures) and how the board appears to them (such as different themes). Username-based software may provide for anonymity by allowing visitors to post without registration.