Chords by root and inversion
Root and inversion is the default way to look up chords. You choose the root note and the inversion, and the list shows every chord type built on that root.
Choose a root and an inversion
The row of note names at the top sets the root. Below it, the segmented control sets the inversion: root position, first, second, and so on. The list updates to every chord built on that root, in the chosen inversion. The funnel button opens a filter to limit which chord types appear.
What an inversion is
A chord is a set of notes. An inversion is the same set of notes with a different one as the lowest. Root position has the root note at the bottom. First inversion moves the root up an octave, so the next note becomes the lowest, and second inversion moves the next one up as well. The notes and the chord name do not change, only which note is in the bass. Inversions let one chord move to the next with less distance between the hands.