These are available to everyone and maintained by the Slides team.
This is a set of templates that only you – the signed in user – have access to. Templates can be saved to this group by using the button in the bottom of the templates component (see screenshot below). To delete a saved template, hover over it and press the trash icon.
Team admins on Slides can save templates to a third tab labeled "Team". This group of templates is available to all members of the corresponding team.