There are various Master Pages in WSS 3. The following are
some of them.
For SharePoint Central Administration: The admin.master and
popup.master pages are used for the SharePoint Central Administration content
pages. These pages can be found under the 12 hive template\Admin.
Global Workspace Master Pages: These master pages can be
found under the 12 hive\Template\ GLOBAL.
Basically, if you are looking for different Master Pages in
SharePoint, just look under the Template folder and you might see some of the
Master Pages you are looking for.
By default two Master Page files are used by WSS:
Default.master: As the name might suggest, this is used by
all end user pages (default.aspx, all lists, document libraries, aspx pages,
etc.). This file is located under 12 hive\Template\GLOBAL. You can change the
default Master Page file through SharePoint Designer 2007. I will explain that
Application.master: These master pages are used for
application pages. Again, located under 12hive\Template\layouts.