The term "sole" refers to something that is single or one in number. It can describe an individual item, person, or concept that stands alone without any others of its kind. For example, a sole proprietor is a business owner who operates independently, without partners or co-owners. In a different context, "sole" can also refer to the bottom part of a shoe or foot. This part is crucial for providing support and protection while walking or standing. The sole of a shoe is designed to offer traction and comfort, making it an essential component of footwear.