What is meant by wavepacket and explain how the matter waves are not waves but are wavepackets?

Wave properties of matter can be reconciled with particle properties by combining waves of different wavelengths to form a group of waves called wavepackets. According to uncertanity principle, the position and the velocity of an object cannot both be measured exactly, at the same time. The very concepts of exact position and exact velocity together, in fact, have no meaning in nature. Thus, a matter wave is represented by a wavepacket, rather than a single wave train such that the effect of a particle in motion at any instant of time is confined to a small region in space.