Thin slices of wood are known as Veneer, they are usually 3mm thick. Layers of Veneers are glued one over the other to make thick Plywood. If you side or edge or cross section of plywood, you will see multiple thin veneers glued one above other.
Type of wood & thickness of ply decides cost of plywood. Plywood sheets sold in market are commonly available in sheet size of 8′ x 4′ (8 ft. x 4 ft.).
In our guide Cost of Furniture, we cover cost of making furniture using plywood.