Acetone is a carbonyl compound and more specifically a ketone. Ketones contain a C=O functional group. Acetone is an "enolizable" ketone. Any ketone that has at least one hydrogen atom attached to one of the C-atoms that are directly connected to the carbonyl C-atom is an "enolizable" ketone since equilibration between H-C-C=O and C=C-OH is possible. You can see the structure of the enol in the following item.