Basic gruntfile with concat and uglify tasks

gruntfile.js

module.exports = function(grunt) {
 
  // Project configuration.
  grunt.initConfig({
    pkg: grunt.file.readJSON('package.json'), //<---imports the JSON metadata stored in package.json
    concat:{
      dist: {
        src: [
            'js/libs/*.js', // Selects all JS in the libs folder
            'js/main.js'  
        ],
        dest: 'js/build/production.js', //Output file after concatenating js files
      }
    },
    uglify: {
      build: {
        src: 'js/build/production.js',
        dest: 'js/build/production.min.js'
      }
    }
  });
 
  // Load the plugin that provides the "concat" task.
  grunt.loadNpmTasks('grunt-contrib-concat');
  // Load the plugin that provides the "uglify" task.
  grunt.loadNpmTasks('grunt-contrib-uglify');
 
  // Default task(s).
  grunt.registerTask('default', ['concat', 'uglify']); //<--- adds "concat"  and "uglify" to the default task
 
};