The definition of a prop is a sometimes nebulous thing. We all know that a book or an apple is a prop. But what about a purse or a built- in bookcase? And why is props in charge of manual sound effects and bushes? The confusion stems from the fact that what a prop is and what a prop shop does can be different things. To confound this, one prop shop may have slightly different duties than another; also, the duties of a prop shop in theatre are different then that of a props crew in film. As one final confusion, an individual production may see a slight modification in the duties of the prop shop based on the specific challenges in relation to the workloads of the various shops. A scene shop may build a certain prop because their shop is better equipped for its manner of construction. It is still a prop in the academic sense. After the show, it goes into the prop shop’s storage, and if used again, it is a props person that pulls it from the stock. Likewise, in a future production, the prop shop may be better equipped and can build a similar prop on their own. It is not the scene shops duty just because they built one in the past.
Keep these three confusions in mind when talking about the definition of a prop. Though usually the same, the academic definition of a prop and the practical obligations of a prop shop are sometimes at odds.