A caret is the multipurpose symbol ^ and is commonly referred to as an up-arrow, hat, wedge, chevron or control character. It was first used in handwritten documents as a way to signal where editorial revisions were to be inserted. Over time, it has come to have other uses, such as being used as a cursor for entering text into a word processor, as a mathematical expression and as a symbol for the control key on a computer keyboard.
The term "caret" is derived from Latin origins and means “to be separated from.” In its original form, the caret was often used below a line of handwritten text to express the need for a punctuation mark such as a comma or period. It also was used above the text to signal the need for the addition of an apostrophe, a word or a phrase.
Although it was initially used as a proofreading and editorial symbol, it also is commonly used in mathematics. A caret generally indicates an exponential equation on graphic calculators that do not support superscript functionality, such as 4^4 instead of 44. The symbol was first introduced into mathematics through the Algorithmic Language 1960 (ALGOL60), which was one of the first computer programming languages.
After its implementation into ALGOL60, it began to be implemented into numerous computer programming languages. In addition to exponential equations, the caret is used to indicate other computer programming functions, such as XOR operator, control characters and string concatenation. The symbol is regularly used in several programming languages, such as Pascal and C++, and in some computer operating systems.
A caret also is used in the systematic study of logic and reasoning. In the realm of logic, it is referred to as a wedge symbol and is used as a logical operator to connect two or more statements. The format is known as logical operator notation, and the caret is a fundamental component of expressing logical conjunction.
Lastly, the symbol is commonly used in music notation, and it often indicates that a specific emphasis should be given to a particular note. In the use of stringed instruments, it indicates that the strings should literally be hammered with the bow. This form of notation is referred to as Martelé or Martellato, and it is used to give notes a distinct effect. In addition to bringing attention to a particular note, it also can be used as a way to reference the particular scale degree of a music composition.
