Insertion marks, also known as carets, are symbols used in writing to indicate where text should be inserted. They are commonly used in word processing programs to indicate where a user should type in new words or phrases. Carets are usually represented by two vertical lines pointing up and down, and can be used to indicate the beginning or end of a sentence, or to mark a specific point in a document. Carets are also used in mathematics to denote an exponent or power.