Barre chord

A barre chord is a chord where the left-hand index finger presses flat across several strings at the same fret, acting like a movable capo. That index finger replaces the nut: a chord shape that was normally played with open strings can then slide anywhere on the neck, keeping the same relative shape. That's what makes a barre chord movable: one memorised shape is enough to play the same chord type in all 12 keys.

A nuance few resources explain: only 2 of the 5 shapes are truly barred

The CAGED system presents five open chord shapes (C, A, G, E, D) as five possible barre shapes. In practice, only the E and A shapes (the ones behind the F and B chords) are actually played as a full 6-string barre: the C, G and D shapes require such a finger stretch that they're almost never used as-is on the neck. That's exactly why Guitarshelf's CAGED tool only shows a full diagram for those two shapes, and simply marks the position for the other three.

The "barre chords" sheet category logically focuses on the E and A shapes.

Barre chord, open chord, power chord: where it sits

An open chord is played near the nut with open strings that give it its ring: but it's locked to that spot on the neck, and every key needs its own shape. A power chord keeps only the root and the fifth (two or three strings, no third): also movable, but neither major nor minor, and physically far easier. The barre chord is between the two: an open shape made movable by replacing the nut with the index finger, with all six strings and therefore the third that commits it to major or minor. You can think of it as a power chord completed by the treble strings.

Practical tips and common mistakes

• Don't barre with the pad but slightly on the side of the index finger (toward the thumb): the skin there is harder and flatter, and doesn't sink into the joint creases.
• The pressure comes from the thumb-and-index pinch, not from arm strength: the thumb sits behind the neck, roughly opposite the index, and the two squeeze toward each other.
• Place the rest of the shape first (middle, ring, pinky), add the index last, then only fix the strings that buzz — no need to re-press everything.
• Move the barre close to the fret, toward the body of the guitar: the closer you are, the less force it takes. The F barre at fret 1 is the hardest spot on the neck — that's normal, it eases up higher.

The F major barre is the open E major shape shifted up one fret, the index standing in for the nut; two frets higher the same shape gives G, two more A. The sheet Barre — isolating the F chord isolates this move.