The community members space tabs allows users who have permission to view the space the ability to see who the current members of the community are. It will also show the users that are invited to become members of the space.
If you want to include the list of members in a page, have a look at the community-members macro
For information on each of the community lists that can be displayed on this screen refer to Community User Lists
Each list can also be filtered to display only users that match a given search string or have been added to the list recently.
This screen also allows community administrators to manage the different user lists. If you are a community administrator you will see an extra link under the filtering options to administer the users in that list. Refer to the Community User Lists for the administration options that apply in each case.