Can someone compare between high action and low action on guitar and which one is better , i don't know too much about them.
TL;DR The short answer (thanks, @RockinCowboy!) is that usually you want your action as low as possible, without hearing any fret-buzz, especially if you are just starting with guitar.
Now the longer answer...
There are advantages to both a higher and lower action on a guitar. In fact, it is often appropriate to have a higher or lower action depending upon the type of guitar. However, it is always possible to have an action that is too high or too low, which can make the guitar difficult or even impossible to play.
Advantages of a higher action:
- allows the player to strike the strings harder without creating fret-buzz.
- allows the player to strike the strings in such a way as to make the strings vibrate "forward-and-back", without creating fret-buzz. This creates a fuller sound, as it makes the soundboard vibrate more. An example of this would be playing with a "deep" apoyando (rest-stroke) on classical guitar, where the string is pressed slightly towards the guitar and then released, making the string vibrate somewhat more back-and-forwards, rather than up-and-down.
Disadvantages of a higher action:
- the player has to press the strings harder with the left hand. This requires more strength, creates more fatigue and can make the fingers more sore.
- as the strings are further away from the fretboard, they have to travel a greater distance when pressed against the frets. This means that you have to bend the string a little more, which can create intonation problems (making most notes sound a little sharp).
Advantages of a lower action:
- hammer-ons and pull-offs (ligados) tend to be much easier to execute.
- as less pressure is required to press the strings, one can generally play more quickly, and with less effort.
Disadvantages of a lower action:
- it can be difficult to bend strings, as the left-hand fingers tend to travel over adjacent strings.
- fret-buzz (see above).
As I mentioned earlier, if the action is much too high or low, the guitar can become extremely difficult or even impossible to play.
If the action is too high it may be impossible to press the strings hard enough to make them reach the fretboard, at some positions along the strings.
If the action is too low you can have a situation where you don't sound the intended note when pressing at a particular fret. For example, you may be fretting at fret 4 with a left-hand finger, but the string may also be touching fret 5 making that note sound instead. (This problem can also be due to frets being worn irregularly, requiring a fret-dress or re-fret.)
Finally, it should be noted that several things contribute to setting up a good action: the height of the saddles and bridge; the curvature of the neck, due to the tension of the truss-rod; the height of the nut (the piece of plastic near the head end of the fretboard). Also, as I mentioned earlier, different types of guitar tend to have different actions. The action of classical and steel-string acoustic guitars, tends to be higher than on electric. This is partly due to thicker strings being used on these instruments, but also the playing techniques that are more commonly used on these types of instruments. Of course, a player that plays gently with light strings on an acoustic guitar may prefer a lower action than someone who plays very hard with thick strings on electric, so personal preference, string gauge and playing style are also important factors.
My original style was electric blues, and this has changed over the years to jazz standards, and solo jazz guitar.
For both styles I prefer heavy gauge strings, and for blues the bigger strings combined with higher action really helps the tone when bending the strings. You have the added advantage of building up strength in your hands and fingers, because a guitar setup this way is NOT easy to play unless you're used to it.
For jazz I prefer the lower action as it makes playing the chord melodys so much easier, and it sounds better as well.