The substances which have definite shape and definite volume are called solids. Solids are hard and rigid. The particles ( atoms, ions and molecules) of a solid are very close to each other or closely packed. Intermolecular forces are present between the molecules of the solid. There are two types of solid including crystalline solids and amorphous solids. The solids in which atoms, ions and molecules are arranged in a definite pattern and three dimensional order are called crystalline solids. In amorphous solids, particles do not posses definite arrangement. Moreover, the shapeless solids are called amorphous solids.