So, here is the first line of code for a new class whose superclass is Object, which is usually the Godhead of all classes. Well, now we are prepared to let the world know what kind of object to expect so lets declare it. First we need to say that we ARE declaring a new class, and while we are at it, define the new class's superclass. That done we put method prototypes. Methods cannot be anything but public, though if I feel like it I may show you a workaround that will generate compiler warnings if you access a private method.
Class methods are only accessible to a class object, and instance of course to instances.
Or, for example, after I declare a variable that will hold an instance, but before I can use it, I must use a class method to create an instance to be pointed to by that variable before I can call any of its instance methods. Once I do, I can not access any of its class methods, only instance methods until I deallocate the object instance. These must not have any spaces in them. Since you're likely very confused, lets look at a class and instance method. Using words inside of the argument structure can make the method make more sense when spoken.