The C augmented chord is a 3-note chord consisting of the notes C, E and G#.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Caug.
Chords that are a superset of Caug. The chords include more notes but always C, E and G#.
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 Caug chord. Feel free to save or share the image as needed.