Bracket

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. Typically deployed in symmetric pairs, an individual bracket may be identified as a left or right bracket or, alternatively, an opening bracket or closing bracket,[1] respectively, depending on the directionality of the context.

Brackets
( ) [ ] { }  
Round brackets
or
parentheses
Square brackets
or
brackets
Curly brackets
or
braces
Angle brackets
or
chevrons

Specific forms of the mark include rounded brackets (also called parentheses), square brackets, curly brackets (also called braces), and angle brackets (also called chevrons), as well as various less common pairs of symbols.

As well as signifying the overall class of punctuation, the word bracket is commonly used to refer to a specific form of bracket, which varies from region to region. In most English-speaking countries, an unqualified 'bracket' refers to the round bracket; in the United States, the square bracket.

Various forms of brackets are used in mathematics, with specific mathematical meanings, often for denoting specific mathematical functions and subformulas.