A self-tape is an audition you film yourself and send in. You get sides, you get a due date, and instead of driving to a casting office you record it and upload it. That’s how most auditions happen now. The room barely exists anymore.
Which sounds easier, and is actually harder. In a room, you got the read either way. On a tape, you’re competing with the tape itself. Bad light. Bad sound. A reader who’s your roommate and now resents you. Casting is watching three hundred tapes, and yours has to survive the first eight seconds.