I'm guessing he means actual time physically working, not the theoretical time in the contract.

It really depends on your bubble but a lot of people have "full time" contracts (meaning 40-ish hours) but real hours vary. You can come later, leave earlier, go do something else in the day, and don't have to report it to anyone. Just make sure you're not missing a meeting and deliver what's needed on time. So in practice you end up working fewer hours on average, as long as you can produce enough on average (which honestly isn't hard in many large organisations, and hard to measure).