TTFT means “time to first token”: how long it takes before the first piece of an AI answer appears. TPS means “tokens per second”: roughly how quickly more pieces arrive while the answer is being made.
Think of waiting for a drink: TTFT is the time until the first sip is ready, while TPS is how quickly the rest is poured. Both can affect how responsive a tool feels.
These are technical measures, not a guarantee that the answer is useful. A fast reply can still be wrong, and total waiting time also depends on the request and the amount of information produced.