The term "sole" refers to something that is single or one of a kind. In various contexts, it can describe an individual item, such as a shoe sole, which is the bottom part of a shoe that makes contact with the ground. It can also refer to a person or entity that operates independently, like a sole proprietor, who runs a business alone without partners. In legal and financial contexts, "sole" often indicates exclusive rights or responsibilities. For example, a sole custody arrangement grants one parent full legal and physical custody of a child. This term emphasizes the singular nature of ownership or control in various situations.