The left bracket is used to pair with a right bracket to enclose a range of data or elements in programming languages, mathematical formulas and scientific notations. There are several synonyms for the left bracket, including open bracket, starting bracket, left parenthesis, and left square bracket. Open bracket and starting bracket are commonly used in programming languages like Python and Java. Left parenthesis is mostly used in mathematical notations and equations, while left square bracket is used to denote an array or list object in many programming languages like JavaScript and PHP. Despite the different names, all of these symbols serve the same function of enclosing a set of data or values.