You know the drills of a taxi driver, right? You need to search for people that wants to go somewhere and drop them to their destination. Now, Sims is a popular game in the PC and it involves real life. The popularity that SIMS got is based on the fact that gamers get to connect the game with real life facts. To simply put it, it helps gamers to experience the life of real people.
In this game, you need to pick up the customers and drop them off to their destination. Now, you can search for a customer and pick them up or you can just wait for a call from your station. Either way, you get a customer and you will get paid after bringing them to their destination.