I won't be going in depth into that, but I would recommend those who do have a keen interest in programming or Computer Science to read up on that, since it is the foundation of high-level programming. Anyhow, Java being an OO language requires the use of classes , objects , methods and variables . The best way to think of their relationships is that a class contains everything you need to know about the object including all the things it can do. Methods and variables are contained inside the class. Methods define what the object can do and are also used to manipulate it.
Variables are parts or specs of the object.
If you find that hard to grasp, consider an object in real world terms such as a car. The car will then be an object and the Car class will c ontain everything you need to know about the car including things to manipulate it. As well, the max speed and distance travelled will be variables. In this case, the class Car defines the Car object. In the above example, lexus is the same as name.