Emails Letters and Mailing Lists-Documents and templates
From Support Wiki
Communication created may be saved for future use in one of two ways - - as a document or a template.
Saving a document allows you to name and save the communication piece to be retrieved at a later time, modified, and saved again. Saving a template allows you to save the communication piece to be retrieved at a later time but will not allow any modifications to be made to the original, thus maintaining the integrity of that communication piece.