The document discusses the structure and functions of the cell. It describes that the cell was first discovered by Robert Hooke in 1665 and is the basic structural and functional unit of life. There are two main types of cells - prokaryotic cells which lack a nucleus, and eukaryotic cells which have a nucleus and membrane-bound organelles. The structures of the cell discussed include the plasma membrane, nucleus, cytoplasm, ribosomes, endoplasmic reticulum, Golgi apparatus, mitochondria, lysosomes, peroxisomes, and cytoskeleton. Each structure performs important functions essential for cellular activities.