A cellular system refers to the network of cells that communicate and work together within an organism. Cells are the basic building blocks of life, and they perform various functions necessary for growth, repair, and maintenance. This system includes different types of cells, such as muscle cells, nerve cells, and blood cells, each specialized for specific tasks. In addition to individual cells, the cellular system encompasses how these cells interact with each other and their environment. This interaction is crucial for processes like cell signaling, where cells send and receive signals to coordinate activities, ensuring the organism functions effectively and responds to changes.