What do you mean by rumination?

Rumination is a process that occurs in certain animals, known as ruminants. It involves the following steps: Animals quickly swallow their food, which is often grass. The food is stored in a part of the stomach called the rumen. Later, the partially digested food, known as cud, returns to the mouth. The animal then chews the cud thoroughly before swallowing it again. This process helps in the digestion of tough plant materials, particularly cellulose, which many animals, including humans, cannot digest effectively