What exactly is a premise?

knottie0ce291a86c3d5ba8

<div>I keep looking for writing advice and it always tells me to start with a premise but I have no idea what a premise is supposed to be. I feel like the reason I can't write jokes that well among other things is that I don't really know what a premise is supposed to look like.</div><div>Every thing I've read gives me a vague description. Such as it's a negative opinion but they never give a solid example</div>