The A minor chord is a 3-note chord consisting of the notes A, C and E.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Am.
Chords that are a superset of Am. The chords include more notes but always A, C and E.
Chords that are a subset of Am. These contain less notes but all of them are included in Am.
In case you prefer a non-interactive variant of the chord chart, we've embedded a PNG image below that shows the notes for the the Am chord. Feel free to save or share the image as needed.