The E flat major chord is a 3-note chord consisting of the notes Eb, G and Bb.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as EbM.
Chords that are a superset of EbM. The chords include more notes but always Eb, G and Bb.
Chords that are a subset of EbM. These contain less notes but all of them are included in EbM.
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 EbM chord. Feel free to save or share the image as needed.