A "signature" is a person's name or a mark made by an individual to indicate approval or authenticity. It is often used on legal documents, contracts, and letters to confirm that the person agrees with the content. Signatures can be handwritten or created digitally, and they serve as a unique identifier for each individual. In many cultures, signatures hold legal significance and can be used in place of a formal agreement. The act of signing is a way to express consent and is often required for important transactions, such as buying a house or opening a bank account with a bank.