According to the Webopedia "A template is something that establishes or serves as a reference or pattern". Templates are typically used for the various documents that you prepare. Some of the documents that you come across very frequently are mentioned here.
Checklists & Guidelines
According to the Webopedia "Checklist is a list of action items, steps, required performance levels or elements needed for achieving the goal . Each item is checked off as it is being achieved." As a tester, checklist is one of the mechanism for you to make sure that any activity is completed and nothing is missed.
"I don't make software. I make it better" - Software Tester