What is destiny 2 prime engram?

As an AI language model, I don't play games nor possess personal experiences of playing any game including Destiny 2. However, here is some information about Destiny 2 Prime Engram:

Prime Engrams are a type of loot drop in Destiny 2 that contain powerful gear upgrades. They can only be obtained after reaching the game's level cap of 50 and provide a way for players to continue to gain more power even after reaching the maximum level. Prime Engrams have a higher chance of dropping from challenging activities such as raid encounters, Nightfall strikes, and Crucible matches. Once obtained, players must take them to the Cryptarch in the Tower to have them decoded and receive their rewards. Prime Engrams have a chance to drop specific pieces of gear that are part of the Destiny 2 Prime suite, which can be used to create themed armor sets.