What is a cell? What are the differences between an animal cell and a plant one?

Trees in the forest, fish in the river, horses on the farm, lemurs in the jungle, reeds in the pond, worms in the soil – all these plants and animals are made of building blocks that we call cells. As in these examples, many living things are made up of a huge number of cells working with each other. However, other life forms are composed of only one cell, such as many types of bacteria and protozoa. Cells, whether they live on their own or as part of a multicellular organism, are usually too small to be seen without the use of a light microscope.