Have you ever been on an airplane and seen those big trolleys that flight attendants push down the aisle? They're called airline service trolleys! They are basically like a big cart that the flight attendants use to serve food and drinks to people on the plane.
These trolleys are really important because they help make sure that everyone on the plane can get something to eat or drink when they need it. The flight attendants fill the trolleys with lots of different things like soda, juice, water, snacks, and sometimes even hot meals!
Once the trolley is loaded up with all of the goodies, the flight attendants will push it down the aisle and give things out to the passengers. Sometimes they'll come to you and ask what you'd like to drink or eat, and other times they'll just have everything already laid out so you can pick what you want.
One cool thing about these trolleys is that they're designed to fit really nicely in the aisle of the plane, even though it can be a pretty narrow space. They have wheels on the bottom so they can roll smoothly and be easily moved around.
So, in summary, airline service trolleys help flight attendants serve food and drinks to people on the plane, and they're designed to fit nicely in the narrow aisle of the airplane.