You want to know how to get big arms, and I assume quickly, so I won’t waste your time with fancy exercises which don’t work very well. Instead, I will give you several of the best exercises for complete arm development.
The Biceps
The most effective exercises to build on the biceps are standing barbell curls with a straight bar, incline dumbbell curls or preacher curls.
The Triceps
To build the triceps you need to begin using close grip bench pressing and triceps extensions such as French curls, dumbbell triceps extensions or skull crushers.
The Forearms
The forearms are easy to develop. All you need to do to develop the forearms is do wrist curls and reverse wrist curls both together with a barbell or separately with dumbbells.
In this article I have not included how to develop the very tops of the arms because they are more classed as the shoulders. For this, see my article How To Build Shoulders Fully With 6 Exercises.