Absolute zero is the lowest imaginable temperature. It is charecterized by 0 entropy configuration. It is the coldest temperature theoretically possible and cannot be reached by artificial or natural means.
At absolute zero the molecular motion is minimal.
By international agreement, absolute zero is defined as precisely 0 K on the Kelvin scale.
It is a thermodynamic (absolute) temperature scale, and −273.15° on the Celsius scale.
Absolute zero is also precisely equivalent to 0 R on the Rankine scale (same as Kelvin but measured in Fahrenheit intervals), and −459.67° on the Fahrenheit scale.