Retrieval is basically Capture The Flag.
In Retrieval, each team defends their own data canister which contains sensitive information that must not fall into enemy hands. Your objective is to steal the enemies' canister and return it to your team's canister base. You cannot score points if your canister is in the hands of the enemy. Just remember to keep your own base carefully guarded or the opposing team might steal your canister
In order to prevent players from camping with the bomb or the retrieval canister, the game does not allow players to take it into their base. If you enter your spawn, you will see an onscreen notification indicating that you have dropped the bomb or canister. Simply go back, pick it up and return to the main gameplay area outside of your spawn.