Webpack and Gulp, grunt nothing comparable, it can be seen as a module Packer, through the analysis of your project structure, to find the JS module and other browsers can not directly run the expansion of the language (Scss,typescript), It is converted and packaged into the appropriate format for use by the browser. Gulp/grunt is a tool that optimizes the development process of the front-end, while Webpack is a modular solution, but the Webpack's advantage is that it can be used in many scenarios to replace Gulp or grunt-class tools.
There are also big differences in the way they work:
Grunt and gulp work in a configuration file that indicates specific steps for tasks such as compiling, combining, and compressing certain files, which can be done automatically for you after the tool.
The way Webpack works is to treat your project as a whole, With a given master file (for example: Index.js), Webpack will start to find all dependent files for your project from this file, use loaders to process them, and finally package them as one (or more) browser-aware JavaScript files.
Webpack and gulp, grunt difference