The rest parameter syntax allows a function to accept an indefinite number of arguments as an array, providing a way to represent variadic functions in JavaScript. Now, What is variadic function ? In mathematics and in computer programming, a variadic function is a function of indefinite arity, i.e., one which accepts a variable number of arguments. Support for variadic functions differs widely among programming languages. What is Rest parameter A function definition’s last parameter can be prefixed with “…” , which will cause all remaining (user supplied) parameters to be placed within a “standard” JavaScript