Heads Up Look above you and be prepared to move. Something is coming down. The big curtain that separates the stage from the audience. Proscenium Arch that separates audience from stage. Pipes Long pipes above your head on the stage.
Pipes are what things hang from.
Pit Lowered area in front of audience for orchestra. Pools, or specials Stationary lights shining on the stage to highlight a dancer. Prop Something small enough to carry onto the stage and use. Visible to the audience. Touch only your own props.