Aarti Gupta
Lattice points-- Crystalline solids are characterised by definite orderly arrangement of the constituent particles in three-dimensions.The particles present in a crystal are relative to one another are shown by points.Such positions are occupied by atoms,ions,or molecules in the crystal lattice are called as lattice points or lattice sites.When these lattice points are arranged infinitely they constitute space lattice.
Coordination number-- The number of spheres which are touching in a given sphere is called the coordination number.For ex-in hcp and ccp arrangements coordination number is 12.Besides that coordination numbers 4,6,8 are also very common in various types of crystals.