Ⓐⓝⓣⓞⓝ (racingisawesome)

A crystalline solid has long-range order. In other words, its atoms or molecules lie in an orderly arrangement that is repeated over long distances. When the crystal melts, that long-range order is lost. In the liquid, the kinetic energy of the molecules can partly overcome the intermolecular forces, and so the molecules are able to move past one another.