Absolute zero and 0 Kelvin are the same thing. They both represent the lowest possible temperature that a substance can reach.

Here's why:

* Absolute zero is a theoretical concept representing the point where all particle motion ceases.

* Kelvin (K) is a temperature scale that starts at absolute zero.

So, 0 Kelvin is the numerical representation of absolute zero on the Kelvin scale.

Here's a breakdown:

* Celsius (C): Freezing point of water: 0°C, Boiling point of water: 100°C

* Fahrenheit (F): Freezing point of water: 32°F, Boiling point of water: 212°F

* Kelvin (K): Absolute zero: 0K, Freezing point of water: 273.15K, Boiling point of water: 373.15K

The Kelvin scale is used in science because it's a "true" temperature scale, starting from the point of no particle motion.