In a p-type semiconductor, holes are the majority charge carriers.
Semiconductors are materials that have conductivity between conductors (such as metals) and insulators (such as rubber). In a pure semiconductor, such as silicon or germanium, there are equal numbers of positive (holes) and negative (electrons) charge carriers, and the material is called intrinsic semiconductor.
However, by adding impurities to the semiconductor material, we can change its electrical properties. When we add impurities such as boron, which has one less valence electron than the semiconductor material, the boron atom can bond with the semiconductor material leaving a "hole" in the crystal lattice where there should be an electron. These holes are positively charged and can move through the material like a particle.
In a p-type semiconductor, the majority of charge carriers are these positively charged holes, while the minority carriers are negatively charged electrons. Therefore, when a voltage is applied, the holes are the ones that move and contribute to electrical conductivity, while the electrons do not move much.
As a result, the electrical resistivity of the p-type semiconductor increases because the majority charge carriers (holes) have a lower mobility than electrons.