Wood decay is the process by which wood deteriorates due to the action of fungi, bacteria, and other microorganisms. These organisms break down the cellulose and lignin in the wood, leading to a loss of strength and structural integrity. Factors such as moisture, temperature, and the presence of oxygen can accelerate this process. There are different types of wood decay, including brown rot, white rot, and soft rot. Each type affects the wood differently, with brown rot causing the wood to become brittle and crumble, while white rot results in a lighter, spongy texture. Proper maintenance and treatment can help prevent wood decay.