If you want the complete answer you should take a look at the following post What are the different cached objects in the plan cache? from the SQL Programmability & API Development Team Blog.

[quote]

 The following caches are included in procedure cache :

  1. Compiled Plans
  2. Execution plans 
  3. Algebrizer tree
  4. Extended Procs 
  5. Inactive Cursors

[/quote]