Biochar is formed at different temperatures and in a different manner than regular charcoal. When formed at temperatures upwards of 600 C, the maximum amount of pores are maintained in the structure of the biochar. It is these pores that tremendously increase the surface area of the biochar, and increase the amount of water that the biochar can absorb and hold onto.
This in turn significantly increases the number of micro organisms that can then populate these moisture laden stable carbon environments. Biochar becomes an excellent, stable landscape in which the soil biology can thrive.