Cats rarely meow at each other, but often meow at people. Some scientists believe this is because cats already know how to communicate with their own kind but reserve meowing for talking to their inferior human owners.
Cats commonly meow because they want to eat. A second reason is because they want to go in or out. Usually cats want to come inside the moment they asked to go outside, and then they want to go back outside as soon as you bring them back inside. A third common reason cats meow is just to socialize with humans. A meow may be a cat’s way of saying, “What’s up?” or “What have you done for me lately?”