Chords tab explained

In Key bar choose key (tonality,root) and from vertical menu bar on the left choose chord type you want to be displayed.

 

 

Barre & others

this table shows list of Barre and other moveable chord shapes (voicings).
Barre chords (sometimes misspelled as Bar chords) are a type of guitar chord where one or more fingers are used to press down multiple strings across the guitar fretboard.Barre chords are often referred to as “moveable” chords, as they can be moved up and down the neck as needed to transpose chord from one to another key.

Open chords

are those that contains one or more open (empty)strings.

Formula in degrees of Major scale

is how chord is constructed using major scale as base.
Formula 1,3,5 for Cmaj means that Cmaj is formed by putting together 1st,3rd and 5th degree of C major scale(C,D,E,F,G,A,B) and it gives that Cmaj contains C,E,G notes.

Formula in degrees of chromatic scale

is same as above except in for scale used as base for constructing chord.In this case as base scale used is so called chromatic scale.The chromatic scale is the scale that contains all twelve pitches of the Western tempered scale.All the other scales in traditional Western music are subsets of this scale including Major scale.
So formula 1,5,8 for Cmaj means that Cmaj is formed by putting together 1st,5th and 8th degree of C chromatic scale.As C chromatic scale consists of all 12 notes starting with note C (C,C#,D,D#,E,F,F#,G,G#.A,A#,B) it gives that Cmaj contains C,E,G notes.

Successive half-steps(frets),zero on key

this is an guitar oriented way of representing chord(or scale) formula.It simply say how many frets is next fret from previous(going toward higher notes).Here is assumed that starting fret (zero fret) is always the same as root(key).

For example:
Successive half-steps(frets),zero on C 4,3,5
That is: Start from C go 4 frets to find E. Then from E go another 3 frets to find G.Then from G go another 5 frets to find C in next octave.