Wood rot is a type of decay that affects wooden structures, caused primarily by fungi. These fungi thrive in damp, humid conditions and break down the cellulose and lignin in wood, leading to weakened and discolored material. There are two main types of wood rot: dry rot and wet rot. Dry rot occurs in dry wood but can spread through moisture, while wet rot requires high moisture levels to develop. Both types can compromise the integrity of wooden structures, making it essential to address moisture issues and treat affected areas promptly.