A bracket is either of two tall fore- or back-facing punctuation marks commonly used to isolate a segment of text or data from its surroundings, with different meanings in British and American English. In British usage, there are four primary types of brackets, known as round brackets , square brackets, curly brackets, and angle brackets. In American usage, these symbols are known respectively as parentheses, brackets, braces, and chevrons . Thus, when the word bracket is used without qualification, in British English it means ( and in American English it means [. There are also various less common symbols sometimes considered brackets. Brackets are typically deployed in symmetric pairs, and an individual bracket may be identified as a 'left' or 'right' bracket or, alternatively, an "opening bracket" or "closing bracket", respectively, depending on the directionality of the context.