Class

Definitions- 

Class is a blueprint or template from which objects are created.

Class is a logical representation of object.

A class can have data members, objects, constructors, methods, nested classes etc

Class doesn’t allocated memory when it is created.

Class defines data members and methods which objects can implement.

Syntax –

modifiers class className{

}

Object

Definitions-

Object is an instance of a class

Object is considered as a real world thing.

Object is a physical entity.

Object uses data/state and methods/behaviour.

Object allocates memory when it is created.

Syntax(in general)-

ClassName objectName= new ConstructorName();

Note- ways to create object in java – new keyword, newInstance() method, clone() method, factory method and deserialization.