The vBulletin CMS allows you and your users to create, edit and publish articles directly to your site. It combines a simple to use content manager with a unique organizational system that lets you control the smallest detail of the site from the number of sections, to the overall layout, to the placement of widgets and displays on each page.
The wiki adds an article system to the Vault-Tec Multiplayer Mod Forums. Depending on how the administrator has configured this system, you will likely be using it to view or contribute to a knowledge base.
The Blog system gives you your own personal space at Vault-Tec Multiplayer Mod Forums. Depending on how the administrator has configured the blog, you will be able to create your own entries and control who may view them.