Time-Of-Flight (TOF) is a measurement technique that uses the time it takes for a signal to travel from one point to another to determine the distance between them. It is commonly used in physics, chemistry, and engineering to measure distances, velocities, and other properties of particles and objects. TOF is based on the fact that the speed of light is constant, allowing the distance between two points to be determined by measuring the time it takes for a signal to travel between them.