I got it..... you want to learn Java, but don't want to read!
Let me see if find just the definition and forward to you.

class variables are static variables declared in class  .Those are not belongs
to any particular instance  and can be.
Instance variable  are those non-static member varibles,which are accessed
using
object refrence.

Class variables are also known as "static variables." They have the same
value among all instances of a class...considered "shared" variables.
Instance variables belong to specific instances of a class. "Objects"
are what we call instances of a class. Look at the example  below. The
variables and methods marked "static" belong to all Martians. The others
are unique to each individual Martian (alice and marvin).

class Martian {
private static int martianCount = 0;

private String name;
public Martian(String martianName) {
martianCount++;
name = martianName;
}

public static int getMartianCount() {
return martianCount;
}
}

Martian alice = new Martian("Alice D. Martian");
Martian marvin = new Martian("Marvin T. Martian");

i probe that "all variables that doesnt have static key word cant be class
variable" am i correct.

That is correct. Class variables are those identified as "static."

This is a brief explanation of Variables in Java.
Java has three kinds of variables:
1. local (automatic)
2. Instance
3. Class
Local variables are declared within a method body. Both instance  and
class variables are declared inside a class  body but outside of any method
bodies. Instance and class variables look similar, except class variables are
prepended with the static modifier.
Again an instance variable  occurs once per instance of a class; that is, every
time you create a new instance of the class, the system allocates memory for all
of the class's instance variables. This is in constrast to class variables which
occur once per class regardless of the number of instances created of that
class. The system allocates memory for class variables the first time it
encounters the class.