How could you help me understand what a class means? I am confused between methods and classes?

Think of it this way:

You, David, belong to a class named "human". There is a general class that defines common things that all humans share. So class is a general concept from which particular objects are created: David, John, Maciej etc. They all have some attributes (variables), but these variables will differ: the variable name will be different for each human. height for someone will equal to 190cm, for someone else it will be 155cm. The weight variable for someone will be 50kg, for someone else - 100kg. All humans (objects belonging to class "human") will also have some methods - things they can all do, for example .sleep, .eat etc. So to sum up: class is an abstract representation of objects that have some stuff in common, and methods are things that these objects can perform, either defined by you or by default Ruby library.