The layer of the Open Systems Interconnection (OSI) model provides services that support users’ tasks, such as file transfers, database access, and e-mail.

The application layer

Explanation:

Layer seven, is the top layer of the OSI and TCP / IP models. There are many application layer protocols

More detail of the application layer:

well cos like a ds it doesn't really die out, unlike for example, fifa, they always come out with a new version, so lets say your fifa 18 is charging you to update the teams and stuff, so, if messi were to go to real madrid (never gonna happen) it would switch messi to the other team, until the owners of fifa come out with fifa 19, then the game would eventually stop updating, and back to the ds, it doesn't really stop working after sometime because there's lots of things that it could be used for, and idk if u know what i'm saying, but long story short, samsung, represents the ds, if they still work, and people love them but not the new version, the old version still works, so they don't really force people to buy new phones, get me?

none because it's so obvious