Fat cells, also known as adipocytes, are specialized cells in the body that store energy in the form of fat. They play a crucial role in regulating metabolism and maintaining energy balance. When the body consumes more calories than it needs, excess energy is converted into fat and stored in these cells. Conversely, when energy is needed, fat cells release stored fat to be used as fuel. There are two main types of fat cells: white adipose tissue and brown adipose tissue. White fat cells primarily store energy and insulate the body, while brown fat cells generate heat by burning calories. Both types are essential for overall health, influencing weight, metabolism, and even hormone regulation.