A shoe tree is a foot-shaped object used to keep the shoe in its original shape and reduce crease formation, thus increasing the lifespan of the shoe.
Quality shoe trees are solid wood, usually cedar, to smell shoes and absorb moisture. Unless they are specific to a shoe model, they are usually articulated by one, two or three springs in the length and width, which allows them to occupy the entire space.
There are also trees for simple shoes, made of plastic or stamped metal, with or without a spring. They are usually cheaper, lighter and more convenient for travel.
Boot trees are shoe trees for boots. Boot trees are often used on ankle-high boots and are similar to standard shoe trees but have a higher ankle area.
Their main function is to support the heel counter, which helps preserve the integrity of the higher heel and prevents it from creasing or folding over. The fore part of the boot tree acts as a standard shoe tree and works to gently stretch out the vamp and prevent creasing.