You use a user selection element to store a list of users
and groups.
Creating a user selection component
You create a user selection component when you want to
reuse a list of selected users and groups in multiple places in your
website.
Adding a user selection element to an item
You add a user selection element to a site area or content
item when you want a select list of users and groups to be used for
a specific site area or content item.
Adding a user selection element to a template
You add a user selection element to an authoring template
when you want the user selection element to be used by a set of items
that use the same authoring template.