Features included in Office SharePoint Server 2007

"Features are modular groups that provide a collection of functionality. Features are available depending on the license type of the Office SharePoint Server 2007 installation, and are activated at various levels of the logical structure of Office SharePoint Server 2007: farm level, Web application, site collection, and site level."

http://technet.microsoft.com/en-us/library/cc678862.aspx

This article contains information about Microsoft Office SharePoint Server 2007 features and the level at which you can activate them.