What is the break between acts of a play or performance during which people are sent out for snacks or stretch breaks called?

The term that specifically refers to the break between acts of a play or performance is "Intermission." This is a scheduled pause that allows the audience to leave their seats for refreshments, stretch, or use the facilities. It is a standard practice in theatrical performances, providing a designated time for relaxation and socialization, which enhances the overall experience of the show.

While "interval" is sometimes used interchangeably with "intermission," it is more common in British English and can also refer more broadly to any break in time, not just in theatrical context. The terms "break" and "recess" are less formal and not typically used in the theatre to refer to this specific pause. Therefore, "Intermission" is the most precise term for this context.