Hi Rahaman!

A Crystal Lattice is the structural arrangement of atoms or ions inside a crystalline solid as points. They are Symmetrical and 3 Dimensional. Each Atom or Ion occupies a single point and these are called Lattice Site or Lattice Point. All these points connected by a straight line, gives us a 3D figure known as Crystal Lattice or Bravais Lattice.

The unit cell of these lattices form a cube. So, the space between the atoms is known as void. Voids are visible in both 3D and 2D structures!

Hope this is helpful!

All the best!