Rate is speed, quota is mileage, shedding is the shop saying "we are full".

Three controls solve three different problems. A rate limit bounds how fast one identified caller goes. A quota bounds how much that caller uses over a long stretch, such as a month. Load shedding looks at the health of the server itself and drops work no matter who sent it. Ask whether the rule depends on the caller or on the server's condition.

Read it once, then a question tests whether the trick stuck.