What about service crew what exactly they do?

Question

What about service crew what exactly they do?

Answer 1

Do you mean the flight attendants?

Their #1 objective is your safety.  They will assist if someone has a medical emergency, or if the airplane needs to be evacuated.  If something happens like the oxygen masks come down by mistake and there is no danger, they try to calm you down and get you to stop screaming.  If you get drunk and start a fight, or try to join the Mile High Club, they are the ones who will bust you.  Their #2 objective is your comfort, so they serve you drinks and maybe a meal, and inform you of what to do if the flight is late and you are going to miss your connection.

If you mean the guys running around the plane on the ground before it leaves the gate, they are putting fuel, food and drinks, etc. into the airplane.  They often connect and disconnect it to/from the airport's electricity (and a/c?) so as to keep you comfy but not waste gas while at the gate.  They empty the plane's toilets.