Braces group statements, declarations, loops and control structures.
Braces also enclose comments, coding, chemical formulas, method bodies, constructor bodies, class contents and interfaces.
Braces are used to enclose numerical sets and to indicate choices and are seldom used in formal writing.
Brackets enclose arrays (systematic arrangement of objects) of information, isotopic prefixes such as [3H] and enclose chemical concentrations such as [CA2+].
Brackets are also used for clarification along with quotation marks and inside of parenthetical information.
Use brackets to indicate errors in and to revise quotes, and to indicate the origin of words.