Brackets

Brackets are punctuation marks used in pairs to set apart or interject text within other text. In computer science, the term is sometimes said to strictly apply to the square or box type.

There are four main types of brackets:

round brackets, open brackets, or parentheses: ( )
square brackets, closed brackets, or box brackets: [ ]
curly brackets or braces: { }
angle brackets, diamond brackets, or chevrons: < >
All these forms may be used according to typographical conventions that may vary from publication to publication and may vary even more from language to language.

Source: http://en.wikipedia.org/wiki/Bracket