Formwork provides support for concrete until it gains strength to support itself. There are several types of formwork components including timber, plywood, metallic, plastic, fabric, stay-in-place, and permanent insulated concrete formwork. Each type has advantages such as durability, flexibility, and cost-effectiveness. Timber formwork uses boards to form a cavity structure, while plywood provides a lightweight and durable system. Metallic formwork uses steel plates and bars to form structures.