Site collections

• A site collection is a group of sites organized into a tree structure.
• A site can either be a sub site or a top-level site that stores the common templates and components for the entire group of sites below it.
• A sub-site has a parent and may also have additional sites below it.
• An individual site, whether it is a top-level site or a sub site, can have its own security and access profile. Similarly, a sub site may be configured to inherit the access rules of its parent site.