collection of objects talking to other objects by invoking each other's methods. Every object is of a certain type, and that type is defined by a class or an interface.

A template that describes the kinds of state and behavior that objects of its type support.

At runtime, when the Java Virtual Machine (JVM) encounters the

new keyword, it will use the appropriate class to make an object which is an

instance of that class. That object will have its own state, and access to all of

the behaviors defined by its class.

the

values assigned to an object's instance variables make up the object's state.

Methods are where the class' logic is stored. Methods are

where the real work gets done. They are where algorithms get executed, and

data gets manipulated

All the Java components —classes, variables, and methods—

need names. In Java these names are called identifiers, and, as you might expect,

there are rules for what constitutes a legal Java identifier.