Rotate Tires

We are planning today to go to town for many reasons. We need to shop for a wedding present for my sister, cash a check and rotate the tires before making a long road trip this Thursday. I haven't yet seen how the car shop will rotate the tires. My hubby said that it won't take a lot of time to do that. He told me what would happen but I can't picture it. We grew up without having a car in the family and that's why I am naive about car things.