"A cell is defined as the smallest, basic unit of life that is responsible for all of life's processes." Robert Hooke was the first Biologist who discovered cells. Cells are the structural, functional, and biological units of all living beings. A cell can replicate itself independently. Hence, they are known as the building blocks of life. A cell consists of three parts: the cell membrane, the nucleus, and, between the two, the cytoplasm. Within the cytoplasm lie intricate arrangements of fine fibres and hundreds or even thousands of minuscule but distinct structures called organelles. Each organelle has its specific function to help the cell survive. The nucleus of a eukaryotic cell directs the cell's activities and stores DNA. Eukaryotes also have a Golgi apparatus that packages and distributes proteins. Core organelles are found in virtually all eukaryotic cells. They carry out essential functions that are necessary for the survival of cells harvesting energy, making new proteins, getting rid of waste and so on.