The berry bush is one of the most plentiful sources of food and can be readily found early in the game. When harvested, the berry bush drops 2 berries. After a period of time the berry bush will regrow it's berries and may be harvested again making it a continuous source of food.
You may dig up a berry bush using a shovel to place it elsewhere. This allows you to place many berry bushes in a single location for easy harvesting.