As has been mentioned in previous section, Gulp is a JavaScript task runner. It helps with performing repetitive tasks like minification, compilation, unit testing, linting, etc. This is possible thanks to extensive Gulp Plugins library.
Gulp tasks are already set up for you. They are stored inside MStore/gulpfile.js. But in order to have access to them via you Command Line tool you will need to install gulp-cli node package. Gulp CLI stands for Gulp Command Line Interface. 
              To do that type following line in your terminal:
            
.js files found inside vendor folder in one vendor.min.js file which are linked to your HTML document..css files found inside vendor folder in one vendor.min.css file which are linked to your HTML document.theme.js file from src folder to dist/js/theme.min.js file which linked to your HTML document..pug template files into HTML. Again from src to dist folder..scss files into non-minified CSS (css/theme.css). From src to dist folder..scss files into minified CSS (css/theme.min.css). From src to dist folder.watch task. It will watch changes of your .scss / .js / .pug files and automatically compile them into .css / .js / .html.Now you when you are equiped with all necessary tools and dev invironment is all set you are ready to dive into MStore customization.
Take some time to familiarize yourself with Project Structure.