Cells are living things too, thus they require energy. They get this energy through "eating"
There are different types of cells, therefore they have different eating strategies. Here are some examples:
Animal Cells: Animal cells filled with a jelly like layer called cytoplasm. Cytoplasm contains all of the cells pieces it uses to function.these are like tiny organs, so they are called organelles. One of these organelles is called a vacuole. A vacuole is basically a space for the cell to digest and store food, like a stomach. When a cell floats by something tasty to eat, it absorbs the food particle into its cytoplasm, and creates a vacuole around it, storing it and digesting it. This food is then converted into energy, or, as it is called in cells, Adenosine Triphosphate. Or simply ATP.
Plant cells: Plant cells have a different type of eating. Plant cells are Stationary. They cannot move, unlike Animal Cells. This is because a plant's cells are structured like a brick wall, with each cell interlocking, kind of like the bricks on a patio. Plant cells are held rigidly in place by a structure surrounding their cytoplasm, called the Cell wall. Seeing as it can't move around to catch food, it makes its own, through Photosynthesis. Unique to plant cells, they have an organelle called chloroplasts. Inside these chloroplasts, are chlorophyll, which absorb light and convert it into energy.
Sorry if it was long..............hope it helped!