The Rest Operator ... in JavaScript allows a function to accept an indefinite number of arguments as an array. It's especially useful when working with functions that can take varying numbers of parameters.

Without using rest operator, only specific number of parameters are handled. Extra arguments are ignored.

arguments is an array-like object available inside functions (not in arrow functions).

...args collects all remaining arguments into a real array.

Rest parameters can be used in combination with template strings to make output more readable.

Be careful when passing an entire array as a single parameter along with the rest operator—it will be treated as one value inside args.