Trefoils are a type of plant belonging to the Fabaceae family, commonly known as clover. They are characterized by their three-leaf structure, which is where the name "trefoil" comes from, as "tri" means three and "foil" refers to leaves. Trefoils are often found in temperate regions and are valued for their ability to improve soil quality through nitrogen fixation. In addition to their ecological benefits, trefoils are also used in agriculture as forage for livestock. The most common species include white clover and red clover, both of which provide nutritious grazing options. Trefoils can also be used in landscaping for ground cover due to their low growth habit and attractive foliage.