Using Cvs in Eclipse
this article covers with the proper usage of the Eclipse CVS client
The main branch all developers are normally working on is named HEAD. When it is neccessary to seperate changes without interfering or colliding with the main developing branch and the changes made there.
Read this great howto http://www.eclipse.org/articles/Article-CVS-branching/eclipse_branch.html
the howto explains how to create a new branch and in which way the branch is merged back into the main branch (HEAD)
Tags are used to mark resources to identify them e.g. a specific version (deegree-2.0.1) or developing branch (ExoticWFS). If you are developing the ExoticWFS you have to switch to the ExoticWFS Branch.