In general, FOH refers to anything the audience can see and is open to them, and BOH refers to anything they can’t (back stage). Since the audio techs need to be out in the crowd to make sure everything sounds good to the audience, they are referred to as FOH.
FOH/BOH comes from theatres where the front is considered anything in front of the stage, and anything behind the stage is the back. So FOH also includes the servers and bartenders, and anything else the public interacts with. This carried over from theatre to most performing arts venues.
In general, FOH refers to anything the audience can see and is open to them, and BOH refers to anything they can’t (back stage). Since the audio techs need to be out in the crowd to make sure everything sounds good to the audience, they are referred to as FOH.
FOH/BOH comes from theatres where the front is considered anything in front of the stage, and anything behind the stage is the back. So FOH also includes the servers and bartenders, and anything else the public interacts with. This carried over from theatre to most performing arts venues.