Food contains energy and materials that the body needs to survive but it must be broken down into tiny pieces before the body can use it. The digestive system breaks down the food into tiny pieces in two stages. At the front of the digestive system is the mouth. Here there are the jaws. In many animals the jaws have teeth. The action of the jaws and teeth break up large pieces of food into smaller pieces that can be swallowed.
When the food is swallowed the digestive system produces digestive juices which mix with it. These juices break down the pieces of food into such small bits that they dissolve.
These tiny pieces of dissolved food can be used by the body and they are taken from the digestive system into the blood. The digested foods travel in the blood to the parts of the body where they are needed.