How Do You Define The 'Absolute Zero'?

Absolute zero is the lowest possible temperature that can be theoretically achievable by a thermodynamic system. This is the temperature in which a thermodynamic system gives the lowest energy that is 0 Kelvin or 0 (K). In the SI scale, the unit of the temperature is known as Kelvin. 0 Kelvin or absolute zero corresponds to -273.150C or -459.670F. This is theoretically proved that at an absolute zero temperature a perfect gas would reach to its zero volume. But it is seen that a real gas changes its gaseous state and converts into either liquid or solid state at a higher temperature than that of absolute zero. At absolute zero, a thermodynamic system's molecular energy becomes minimal and not available for transferring to other state. The theory is hypothetical and mathematically proven but the real life application of this concept is yet unknown.