Potato salad is a salad dish made from boiled potatoes, usually containing a dressing and a variety of other ingredients such as boiled eggs and raw vegetables. Potato salad is generally served cold or at room temperature. Ingredients often include mayonnaise or a comparable substitute (such as yogurt or sour cream), herbs, and raw vegetables (such as onion and celery). The early American potato salad was made from cooked potatoes that were typically dressed with oil, vinegar, and herbs.

Source: Wikipedia