Adjusting the action on an acoustic guitar involves changing the distance between the strings and the fretboard. Lowering the action can make the guitar easier to play, especially for beginners or those with smaller hands. It can also improve the intonation and sound quality of the guitar.
There are two main ways to lower the action on an acoustic guitar: adjusting the truss rod or sanding down the saddle. Adjusting the truss rod is the more common method, and it is typically done with a special tool called a truss rod wrench. If the truss rod is too tight, it can cause the neck to bow forward, which will raise the action. Loosening the truss rod will allow the neck to relax and lower the action.