Fork Vs Double attack

“Modern chess is too much concerned with things like pawn structure. Forget it, checkmate ends the game.” – Nigel Short

I have noticed that all newcomers have this suspicion for a long time. Now it has to be crystal clear to us. Let's take a look at their definition first.....

• Fork - It is a tactic in which a piece attacks two or more pieces simultaneously.
• Double attack - It is a tactic which a piece creates two simultaneous threats against their opponent.

Let's take a closer look at this....

See this example....

"Every Forks are Double attack but Every Double attacks are not Fork"