taskHelper helps selecting files for other tasks. For example, you want to minify only changed JS files. Then taskHelper selects files which are newer than dest from src (or newer than the time when this ran last time), and these files are passed to grunt-contrib-uglify task. And, taskHelper helps you do something small to files (or file's contents). For example, rename file, replace text, etc... You can create your custom task to do something easily via grunt.registerTask(). Or, writing new plugin is easy too. Using taskHelper is more easy.