Referenda are simple, inclusive, stake-based voting schemes. Each referendum has a specific proposal associated with it
Referenda are discrete events, have a fixed period where voting happens, and then are tallied and the function call is made if the vote is approved. Referenda are always binary; your only options in voting are "aye", "nay", or abstaining entirely.
All referenda have an enactment delay associated with them. This is the period between the referendum ending and, assuming the proposal was approved, the changes being enacted.
Referenda is considered baked if it is closed and tallied. Again, assuming the proposal was approved, it would be scheduled for enactment. Referenda is considered unbaked if it is pending an outcome, i.e. being voted on.