In the Book The basic principles of the generation of carrier spin polarisation, spin dynamics, and spin-polarised transporthave been discussed. Various concepts discussed include spin transfer, spin transfer torque, spin-pumping force and spin currents, tunneling anisotropic magnetoresistance, and tunnel magnetoresistance in semiconductor magnetic tunnel junction, spin-dependent magnetoresistance in all-semiconductor heterostructure, and magnetic-induced and current-inducedswitching. Applications of spintronics in various fields including research and quantum computers, and the fabrication of the spintronics devices have also been described at length.