The Campaign Templates library is where you'll find the email and SMS templates that belong to your gCast account. You can create new templates, make copies of or modify existing templates, even delete templates that you don't need any more.
The templates are displayed with a thumbnail image and the editor type so you can easily find the one your're looking for based on it's visual content or you can use the filtering and search options to quickly locate the template that you want. Searching will look through the content of your templates as well so you don't need to remember the title of the one you're looking for if you already know what the content referred to.
Hovering over a template will reveal the options to preview a larger version of the template or the option to edit (if you have the appropriate permissions). SMS templates will also show you the character and message count of the template.
If a parent account has shared some templates with you, you'll be able to see them in the Campaign Templates library too but you won't be able to edit or delete them.