The open chords (a.k.a. open position chords or "cowboy chords") are the most common chords in several styles. They are known as open chords because some of the strings are played without a finger placed on them. Another definition is that they span more than one octave, contrary to closed chords (this is more in the context of voicings and piano however).
Some common examples:
All these chords are open, meaning that one or several strings is played loose and not fretted. The chords are suitable for many styles, among some are contemporary pop and singer-songwriter. See progressions further down the page.
Chord note structure
Here is information about which notes each chord consists of and also without duplicates. Observe that you sometimes strum more strings than the numbers of the notes of the chord you are playing, and this is because some notes are played twice (or trice in rare occasions), but in different octaves.
All these chords are open, meaning that one or several strings is played open without any fingers pressing down. The chords are suitable for many styles, among some are contemporary pop and singer-songwriter. Notice that D13 include fingerings on the fourth and fifth fret.
All these chords are open, meaning that one or several strings is played without loose strings and not fretted.
All these chords are in open position, meaning that one or several strings is played without any fingers pressing down. Observe that Gm and Gm7 are more common to play as barre chords and that Gm7 is an inversion (Gm7/Bb). An alternative fingering for G major that also is common is 320033, in which the less open ringing strings gives a more percussive sound.
Some of the F chords are not the standard, but are chosen here to qualify as open chords. Many prefer to play some of the F chords as barre chords instead.
F minor is not included since no proper open position version are available. The same thing with Fm7, Fm6, F6 and some other F chords.
F6 is commonly played as XX3231 (with the 5th omitted), but one alternative as an open chord is 100211.
Some suggestion of possible progressions using the chords illustrated on the page:
C – Fmaj7 – G – C
G – D6 – Em – A7 – G
Em – C – G – Am7
Open chords refer to the way a chord is constructed, by including open strings and is often used to describe a chord that is not a barre chord. There is no accurate term to otherwise describe a chord that is not open and not a barre chord (closed chord as a term in this case is somewhat problematic).
An open chord can be a C or it can be a C7 or it can be a Cadd9. You can in most cases play a certain chord as a barre or as an open chord, the difference is the sound (and the shape of course).
Open chords work very well on a steel-string acoustic guitar or an electric guitar with clean sound from the amplifier. The tones ring out nice and have a pleasant crispy sound.
The drawback with open chords is that some of them has quite difficult fingerings. From the link list above you can choose from notes C - D - E - F - G - A - B whereas C# (or Db), D#, F#, G# and A# are missing. This is because these chords in many cases doesn't have natural fingerings in the standard tuning and because of that often is played as barre chords or with a capo.
The next step after you have learned the common open chords is learning other kinds of chords to put in your chord progressions, such as barre chords and voicings. This can in many ways enrich your sound and give new methods to your guitar playing. It's not about knowing all the chords that exist, but to expand your knowledge and increase the ways you can approach your guitar, either you are playing songs of other's or creating your own.
If you want to know more about the theory regarding chords, read What is a chord?