When we connect p-type region of a junction with the positive terminal of a voltage source and n-type region with the negative terminal of the voltage source, then the junction is said to be forward biased. At this condition, due to the attraction of positive terminal of source, electrons which participated in covalent bond creations in p-type material, will be attracted towards the terminal. As result numbers of covalent bonds are broken and, electrons are shifted towards the positive terminal. As a result, the concentration of electrons in the crystal nearer to the terminal increases and these electrons recombine with holes here. In this way, the number of holes increases in the portion of the p-type region away from the junction, and it is reduced in the portion of p-type region nearer to the terminal. As such holes are shifted from terminal to junction.