Shards is one of the main currencies in Battleborn. Through the Lore, Shards can be obtained by the various factions through Shardjumping, however in the game the best way is to walk over them, or attack the larger pieces and once they drop you'll be able to pick them up. Once you've collected a certain amount of Shards, you can spend them on various Buildables depending on the various Game Modes.
Shards are a form of in-game currency that can be used to build and upgrade buildables as well as activate Gear. Shards are only available for the duration of an individual Story episode or Competitive Multiplayer match and do not carry over to other matches.