What is the difference between intrinsic and extrinsic materials?

Intrinsic - A perfect semiconductor (ex: silicon) crystal with no impurities or lattice defects is called an intrinsic semiconductor

Extrinsic - an extrinsic material is achieved by introducing impurities into the intrinsic material described above, such as doping silicon with boron atoms, such that the equilibrium carrier concentrations are different from the intrinsic carrier concentration.