What Does Non-volatile Mean?

The word non-volatile is simply an antonymous term for volatile which is mostly used for a person or to describe their mood which is considered as ever changing and hardly concentrate on one thing for a long time.
       
As we all know that 'non' is a term that is used to form a negative term out of a positive one, so non-volatile is somebody who doesn't change very easily and can concentrate himself on one thing or subject for a long time.
       
The term has technical uses also and as we use the word 'volatile' for something that can easily change into gas so non-volatile is something that doesn't change easily. Petrol is considered as a volatile substance as it changes its state easily and anything that has opposite quality to that of petrol can be called non-volatile.