The main difference between aioli and mayonnaise comes down to adding garlic. While both are emulsion-based cold sauces, aioli showcases garlic as the star flavor, while mayonnaise takes a more neutral approach. Aioli is a derivative of mayonnaise. So, in an aioli, you'll detect a very forward garlic presence. The garlic flavor will be front and center, unlike the more rounded flavors in regular mayonnaise.