Lignins are complex organic polymers found in the cell walls of many plants, particularly in woody plants. They provide structural support, making plants rigid and resistant to decay. Lignins are one of the main components of wood, along with cellulose and hemicellulose, and they play a crucial role in the plant's ability to transport water and nutrients. In addition to their structural function, lignins contribute to the plant's defense against pathogens and pests. They are also important in the production of various products, such as paper and biofuels, as they can be broken down into valuable chemicals through specific processes.