Definition - What does Facebook Wall mean?
A Facebook wall is part of a Facebook user's profile where the user can post status updates and receive messages from friends. The wall is a public portion of a user's profile in that the user's friends are able to see it. The wall also shows updates of a user's recent activity such as comments the user has posted on other friends' walls, the user's status updates and who the user has recently friended.
The Facebook wall is an interactive feature. Friends can respond to wall posts publicly (wall-to-wall), or privately through a private message. All the message recipient's friends can also comment on the wall post.
Techopedia explains Facebook Wall
In July 2007, Facebook began allowing users to post attachements on the wall. Previously, only text could be posted. The Facebook wall acts as a user's hub. It is used for information the user would like his or her friends to see. Along with with the wall timeline posts, a user can also include information such as employer, birth date, relationship status and religious affiliation, among other facts. Personal messages should not be posted this way and instead should be sent as private messages, which act much like email.