What is the difference between retinoic acid and retinol? Are they the same or almost the same?

Retinoic acid. Both compounds are in the "retinoid" family of drugs. However, they have very different properties. Retinol is not nearly as effective as retinoic acid for acne, facial wrinkling, etc. Retin-a is the most famous of the retinoic acid compounds, but equally effective and cheaper generic products are also available.