What does House left mean?

Now we are going to confuse things. The term “house” is used to describe the seating area for the audience. In a proscenium theatre, that would be everything in front of the apron. “House left” and “house right” refer to your left or right as if you were sitting in the audience looking at the stage.

Which side is stage left?

left side

Stage left is the left side of the stage for an actor who is standing facing the audience.