Here is link to a blog comparing themes with templates:

http://blog.lilybiri.com/whats-in-a-theme-a-template

PLEASE! Do not use a template anymore (cptil-file), since a couple of versions they cause more problems, are very buggy when used especially if you include variables and actions in the template.

If you need this for design reasons, creating a custom THEME is what you need to do. It includes all object styles, master slides, skin, Recording defaults and all based on a custom theme colors palette. Master slides can have placeholders, and you can even use interactive objects with actions on them. If they use variables those will be created as well. Add to that external libraries which can have not only assets but even shared actions and you have a much better solution.

If for any other reason you needs such a file, do not create a cptl file but a cptx file to be used. Lock as much as possible, use master slides extensively and you will not encounter the bugs which exist when using cptl files.

Ctrl+T if you use windows. the other option: file – New project – project template…. And you can build youre template. save it as a template. You can also build a basic module and save this as Captivate Template Files (*cptl)