What is plank length?

The Planck length, approximately (1.6 \times 10^{-35}) meters, is a fundamental physical constant that represents the smallest measurable length in the universe, beyond which the classical concepts of space and time cease to be meaningful. It is derived from fundamental constants: the speed of light, the gravitational constant, and Planck's constant. In theoretical physics, it is often associated with the scale at which quantum gravitational effects become significant, suggesting a limit to the divisibility of space.