abstract method-abstract class

I am new to java technology.
I have one doubt in the following program.
class Test{
public abstract void m1();
}

while compiling i am getting like
Test.java:1: Test is not abstract and does not override abstract method m1() in Test
class Test{
^
1 error
what does it mean.
could you explain what the exact meaning of this compile time error.

Simply, only abstract classes and interfaces can have abstract methods.