Chicken is a very common protein to eat with any meal. Vegetables and side dishes often complement any meal that is served with chicken. Salads are included in those side dishes. In salads that are eaten as a main dish most likely during lunch the cook will sometimes include chicken in the salad. Usually, if a salad is eaten as a main meal instead of a side dish, it usually contains some sort of meat or protein.
Grilled chicken is probably the most common meat added to salad. Sometimes, the salad is made with chicken. Chicken salad is made with chicken being the main ingredient and then mayonnaise and celery and possibly grapes are mixed together to make a spread, but it is called chicken salad.