the.com/setup
The deliberate arrangement of pieces before anything actually happens — physics or comedy.
means The way something is configured, organized, or arranged to function — or the premise that primes a payoff.
from Born from the phrasal verb 'set up,' fused into a noun by early 1900s American English, when slang loved compressing verbs into things you could name and blame.
Comedy lawNo punchline survives without its setup.
Con artist senseA 'setup' means a rigged, doomed-from-the-start trap.
Tech ubiquityEvery device ships demanding you complete one.