A Barre Chord or Bar Chord, is a chord that uses one finger to bar several strings at a time. Typically, the 1st finger would be used to bar all six strings essentially creating a new nut.

Occasionally, depending on how you play, you may bar only a few strings. Take a D chord for instance. You can bar the A and F# notes. The standard A chord can be barred as well leaving out or muting the highest note.

Most bar chords are portable. You can play them at almost any position on the neck. Although, once you get up past the 12th fret they become a bit crowded.

A full bar chord may be referred to as great or full. A smaller bar chord may be referred to as small. The following is an example of the different bar options for a G minor chord:

Bar chords take some practice to sound good. Make sure you can hear all the notes without buzzing or without strings getting muted. This is where having your thumb directly in the middle of the back of the neck comes into play.

G Minor chord with a full bar on the 3^rd fret below.

G Minor small bar chord with a half bar on the 3^rd fret below.  

G Minor triad using a half bar on the 3^rd fret below.

F Major full bar chord with a full bar on the 1^st fret below. 

F Major small bar chord with a partial bar on the 1^st fret below. This chord shape is much easier to play than the full F chord. It also makes it easier to switch from F to C or A minor, etc. 

F Major triad with a partial bar on the 1^st fret below. 

B Minor full bar chord with a full bar on the 2^nd fret below. 

B Minor small chord below. Notice how playing it this way removes the need to make a bar on the 2^nd fret. 

B Minor triad below. Playing the chord this way also removes the need to make a bar on the 2^nd fret. 

B Major full bar chord with a partial bar on the 2^nd and 4^th frets below. 

B Major triad using a partial bar on the 4^th fret below. 

These are just some examples of basic bar chords. You can play major and minor bar chords anywhere on the neck. Bar chords are meant to be moved around the neck. Typically, when playing a bar chord the root note will be where your index finger is. However, there are exceptions to this rule.

E Major bar chord (in the C shape) with a partial bar on the 4^th fret with the index finger below. This is an example of a bar chord that doesn’t have the root note on the index finger. 

B Major bar chord (in the G shape) with a partial bar on the 4^th fret with the index finger below. This is another example of a bar chord that doesn’t have the root not on the index finger.