Bracket vs brace

Question

I found the terms bracket and brace used interchangeably. Is there a difference, and what is it?

Answer 1

"Brackets" is used interchangeably for various symbols:

• angle brackets for <>
• round brackets for ()
• curly brackets for {}
• square brackets for []
• and more, some of which are only used in certain regions or cultures

The more specific "braces" and "parentheses" are almost never used for other than {} and (), respectively. Mathematics has several more (subtle) variations in addition and is formalized more than other fields.

I prefer "braces" for {}, "parens" (informally or in the context of programming) or "parentheses" for (), and plain "brackets" for [], though "square brackets" is sometimes required to be explicit about the latter. This gives you a one-word name for any of those common symbols. (And don't get me started on the problems of angle brackets for grouping... :P)

To provide a non-text counterpoint, "bracketing" in photography is taking multiple exposures around a given value (which value—white balance, ISO, aperture, etc.—depends on what you're targeting). This shows the use of "bracket" to mean "surrounding," which lines up nicely with the text symbols above.

Answer 2

Square brackets [] are often simply called brackets, while curly brackets {} are often called braces (in the US, at least). Someone using the term braces for square brackets is making a mistake, because most people will assume that person means curly brackets. So, these terms are not interchangeable, although braces are a type of bracket.

Answer 3

I am not sure about other contexts, but in texts about programming you will often find these terms used as follows:

braces: {} parentheses: () brackets: [] angle brackets: <>