You can create two types of storage containers on a SharePoint site: lists in which you store information, and libraries, in which you store content. You create lists and libraries from templates—either those supplied with SharePoint or templates created or customized by other people. You can use the template-based lists and libraries in their default form, modify them to fit your needs, or create your own.
A SharePoint team site based on the default template includes three categories of lists:
Communications. Lists in which to share information, including Announcements, Contacts, and a Discussion Board
Tracking. Lists in which to track information, including Links, Calendar, Tasks, Project Tasks, Issue Tracking, and Survey ...