Action also refers to the playability of a guitar. While it's a somewhat subjective area, a guitar is considered to have good action if it takes the same amount of force to fret the strings all the way up and down the fretboard. A guitar with bad action typically takes more force to fret higher up the board. A guitar is also said to have high action if the strings are high off of the fretboard, and low action if they are very close to the fretboard. Most players prefer a guitar with good, low action.