The Skills Matrix tab will show you the Skills of any Resources assigned to the Project (showing on  the Team tab) to help you pick the right person for the Task.

On the top right hand you have the options to Search, Filter by Profiles or Export the table in your preferred format.

If you need to update any Skills, this would be done via Resources > Skills 

Note:  The Skills Matrix tab will only be visible if Skills have been set up:
Skills need to be enabled at Company Level (Admin > Configuration > Company Preferences > Skills - Resources)
Skills then need to be configured  (Resources > Skills > Skills / Capacity Matrix)