The Minecraft server uses a plugin called Graves to store your items in a death chest when you die. This is to help both you recover your items and the server not struggle to keep track of additional floating entities.
When you die, your items are safely stored in a chest, which is placed near or around wherever you died.
Note : You have 3 hours to reclaim your chest before it vanishes, so don't wait!
Graves are not free, they come at a cost! You can craft a grave token to carry with you in the event of death!
When you die...
Find your chest!
You even retain some of your levels! (You lose one...)