People section allows you to see task lists and tasks of other people.
To add a team member to People section just enter an email to the appropriate field:

You can also add a mailing group to People section by entering group email. All members of the group will be added:

Some tasks may be hidden, as you are not a member of appropriate Project/Area and don't have permissions to see the tasks (see Sharing Projects and Areas section).

To remove a person or a group, select appropriate menu item: