A jury only sits in the Crown Court and is made up of 12 members of the public. They are chosen at random, and are supposed to represent the general public with a mix of ages, sex, cultural backgrounds, jobs and so on.
Once they have heard all the evidence in a case, they talk in a private room about what they have seen and heard. They then have to decide whether they think the defendant is guilty or not guilty. If they are sure that theyve seen enough proof to show the person committed the crime, they must find them guilty. If they are not sure, they must find the defendant not guilty. Sometimes it doesnt take long to make the decision, but sometimes it can take days.