Predominantly power chords are played on the bass strings, the E, A and D strings. More often than not the chord will be made using a partial barre, as this allows the musician to play several power chords in the same fret board position without actually moving the barre at all.
Certain simple chord progression, especially those found in the more simple forms of rock music such as punk, will require very little physical movement of the left hand up and down the fret board, allowing the rhythm guitar player to thrash out extremely fast and driving rhythms with the minimum of effort.
There are whole generations of musicians who did nothing more than teach themselves how to play Guitar Power Chords in their own bedrooms, before moving on to learn more complex chords and more intricate musical styles.
Learning to play guitar power chords is fun, simple and offers an immense amount of gratification for a minimum of effort. If you are the kind of new guitar player who wants to be able to play something recognizable within days of picking up a guitar for the first time, then spend a few hours learning to play guitar power chords and jamming along with your favorite rock songs.