How to Construct a Chord

Triads
A triad is three notes to build a chord.

A major triad is built with a major third and a perfect fifth from the root.

A minor triad is built with a minor third and a perfect fifth

A augmented triad is built with a major third and a augmented fifth

A diminished triad is built with a minor third and a diminished fifth

Triad Inversion
Leaving the root, third and fifth alone is called the root position. Example would be that C would be the bass and root note; E would be the third, and the G would be the fifth.

If we move the C an octave higher, this would be called the first inversion. The C is still the root, but the E is still the third and the bass note. The G is still the fifth.

If we move the E an octave higher, this would be called the second inversion. The C is still the root and the E is still the third; but the G is the bass note and still the fifth.

If we move the G an octave higher, things would go back to regular. The C would return to being the bass; the E as the third, and the G as the fifth.

Seventh Chord
A seventh chord is the combination of the triad plus the interval of the seventh

A major triad plus a minor seventh combine to form a dominant seventh chord. Dominant seventh chords are abbreviated with a 7.

A major triad plus a major seventh combine to form a major seventh chord. Major seventh chords are abbreviated with a capital M and a 7. M7.

A minor triad plus a minor seventh combine to form a minor seventh chord. Minor seventh chords are abbreviated with a lowercase m and 7. m7"

A diminished triad and a minor seventh combine to form a half-diminished seventh chord. Half-diminished chords are abbreviated with a slashed circle and a 7.

A diminished triad and a diminished seventh combine to form a diminished seventh chord. Diminished seventh chords are abbreviated with a open circle and a 7.

A minor triad and a major seventh combine to form a minor-major seventh chord. Minor-major seventh chords are abbreviated with a lowercase m, a capital M, and a 7. mM7.

A augmented triad and a major seventh combine to form a augmented-major seventh chord. Augmented-major seventh chords are abbreviated with a plus, a capital M, and a 7. +M7

An augmented triad and a minor seventh combine to form a Augmented seventh chord. Augmented seventh chords are abbreviated with a plus and a 7. +7

Extended Chords
https://en.wikipedia.org/wiki/Chord_(music)#Extended_chords

Altered Chords
https://en.wikipedia.org/wiki/Chord_(music)#Altered_chords

Added Tone Chords
https://en.wikipedia.org/wiki/Chord_(music)#Added_tone_chords

Suspended Chords
https://en.wikipedia.org/wiki/Chord_(music)#Suspended_chords

Borrowed Chords
https://en.wikipedia.org/wiki/Chord_(music)#Borrowed_chords