There are seven main types of plywood that are categorized on the basis of the wood they are made of, the intended purposes, its sustainability, etc.
3-ply and 5-ply: These common types of plywood get their name from their number of layers: e.g, 3-ply has three layers. Uses include: Boxing in or decorative internal uses
Multi-ply: This is composed of many layers. Uses include: Heavyweight construction, e.g., house framing
Blockboard: Not technically a ply, but shares its characteristics. Has two thinner outer layers that enclose thicker, square-cut lengths of wood. It is therefore stiff and durable. May have a decorative veneer or a finish of a lesser grade of wood. Uses include: Ideal for shelves and cabinets, and can be finished with paint
Medium-density fiberboard (MDF): Very versatile. Made up of highly compressed wooden fibers glued together. This method of manufacturing means that cut edges are neater than those on other materials. It can provide a rigid structural component, or can be intricately shaped to form a decorative surface ready for paint. Available in various thicknesses. Main drawback is that it gives off a very fine dust when cut, which must not be inhaled. Wear a mask when MDF is being cut. Uses include: Cabinets, cabinet doors, boxing in, shelving
Moisture-resistant MDF: A version of MDF that can resist moisture attack. It is often green. Uses include: Areas prone to moisture: e.g., kitchen or bathroom
Fiberboard: A lightweight version of MDF. Joints between sheets can be taped, and the boards painted. Uses include: Underlay for flooring, or as an alternative to drywall on a ceiling
Particleboard: Central core is composed of small wooden fibers. Has no decorative quality, so is usually covered. Some sheets fit together using a tongue-and-groove mechanism. Available in various thicknesses. Uses include: Often used as floor sheathing
Moisture-resistant particleboard: More water-resistant than normal particleboard. It is often colored green. Uses include: Flooring
Veneered particleboard: Has a melamine (plastic) or decorative wooden veneer. Uses include: Commonly used for shelves
Hardboard: Thin, compressed fiberboard. Standard hardboard has one smooth side, and one rougher side. Different grades and a variety of finishes are available. Uses include: Often used for parts of kitchen cabinets with a melamine (plastic) surface or veneer.