At 0 Kelvin, we're at the coldest temperature possible which is referred to as absolute zero. We cannot get any colder than this. At this temperature, the molecules aren't moving or vibrating to provide heat energy. The higher the temperature, the more the molecules are moving or vibrating.
The 0 degree mark on the Celsius scale is well above absolute zero. So that allows for negative Celsius temperatures to be possible. The same can be said about Fahrenheit as well. We cannot have negative Kelvin temperatures.
