theater [2]
Establishment built to present plays, shows, dance performances, concerts and so forth.
stage 
The area seen from the house where the artists perform.
lights 
Row of projectors set up above the proscenium.
stage curtain 
Piece of fabric separating the stage from the house.
upstage 
Area at the back of the stage whose set is often made to suggest distant places.
opposite prompt side 
The right side of the stage, from the audience.
prompt side 
The left side of the stage, from the audience.
border 
Horizontal strip of fabric used to hide the parts of the flies that are visible from the house.