An acorn is the nut of the oak tree, belonging to the family Fagaceae. It typically has a hard outer shell and contains a single seed. Acorns are an important food source for various wildlife, including squirrels, deer, and birds. They play a crucial role in the ecosystem by providing nourishment and helping to propagate oak trees when they germinate. Acorns vary in size and shape depending on the species of oak tree. They usually mature in the fall and can be found on the ground beneath oak trees. The process of acorn germination leads to the growth of new oak saplings, contributing to forest regeneration and biodiversity.