Cellular biology is a branch of biology that studies the structure, function, and behavior of cells. This field explores how cells work individually and how they interact with each other to form tissues, organs, and organisms. Cellular biologists investigate various aspects of cell biology, including cell division, growth, metabolism, signaling pathways, and communication between cells. They also study how cells respond to internal and external stimuli, and how these processes are regulated at the molecular level. Understanding cellular biology is essential for advancing our knowledge of various diseases, development, and evolution.