Answer:
Ground is the background surface used to paint.
Explanation:
Also known as prime, ground can be any color, but white is the most common one. It also changes according to the surface used; it helps the paint adhere. According to the different surface, many kinds of ground can be used. Three examples of this are acrylic gesso (for paper); oil and white pigment for canvas; and gesso ground of chalk for woods, even it is not very common nowadays.
