Data Persistence

Data Persistence is a method of saving data for Roblox Places so that the data can then be loaded when the player visits the game again.

45000 DPUnit storage limit
There's a limit on how much data can be stored per player per place - see DataComplexity for details on how much each piece of data counts towards this limit

Only Per-User-Per-Place (PUPP)
Data is specific to both the player and the place - it is not possible to save data to a player that is shared between places (such as having synchronized Computer data saved in TerrainBuilder 3D and the Computer Place, however it is possible to have Computer Block Data save between your world and other player's worlds.)