I want to be able to change the fields in my tasks in a task list.  

For Example I have a Task List called - Decommission.  Under that Task List I have 2 task as follows

-Signed Letter and Servers to Decommission.

In the Servers to Decommission task I want to have a field called Servers to enter infromation into, but I don't want that field in the Signed Letter task?  Is this possible?