If you are starting to work with D365FO then you might want to use the tiles that you find on the workspace. For performance reasons there is a cache that is kept to display the count on these tile if the developer has provided that. You can configure this in the system administration menu.

Here is a quick overview.

D365FO 1611 – Update3 (7.0.4307.16141)

If you are looking for an overview of the tile cache you can refer to this link

Cheers

Lachlan