Gulp and Grunt, both are JavaScript task runners and both do the same job. Let’s first see some similarities.

Both are JavaScript task runner and automate various things like minification, error checking, compiling SAAS or LESS to css and many more…
Both are using npm for installation and rely on Node.js
Both have plenty of plugins to do the all the job.

Now, where they differ:

Gulp prefers code over configuration approach, which makes thing more efficient and manageable.
Gulp uses node stream to reduce file I/O operations while performing any task, where with Grunt performs more file I/O operations. Which makes gulp fast.
Grunt is synchronous by design. Each task will only run after the last task has finished, in a series. On the other hand, Gulp is asynchronous. So you can’t be sure in which exact order the tasks will be finished.
Grunt plugins do more than one job which complicates things, where gulp plugins are clean to do only one job.
Community support is great for grunt as it’s very old, where for gulp, its not that great in comparison with Grunt.
Grunt has more plugins to work with than gulp.

That’s all folk. If you have something to add in this list, please mention in comments section. Meanwhile, share this in your network and spread this to help others.
Below is a sample gulpfile.js for your reference.

var gulp = require('gulp'); 
var jshint = require('gulp-jshint');
var sass = require('gulp-sass');
var concat = require('gulp-concat');
var uglify = require('gulp-uglify');
var rename = require('gulp-rename');
 
// Lint Task
gulp.task('lint', function() {
    return gulp.src('js/*.js')
        .pipe(jshint())
        .pipe(jshint.reporter('default'));
});
 
// Compile Sass
gulp.task('build-css', function() {
    return gulp.src('scss/*.scss')
        .pipe(sass())
        .pipe(gulp.dest('css'));
});
 
// Concatenate & Minify JS
gulp.task('scripts', function() {
    return gulp.src('js/*.js')
        .pipe(concat('all.js'))
        .pipe(gulp.dest('dist'))
        .pipe(rename('all.min.js'))
        .pipe(uglify())
        .pipe(gulp.dest('dist'));
});
 
// Watch Files For Changes
gulp.task('watch', function() {
    gulp.watch('js/*.js', ['lint', 'scripts']);
    gulp.watch('scss/*.scss', ['build-css']);
});
 
// Default Task
gulp.task('default', ['lint', 'build-css', 'scripts', 'watch']);   _{Your Comment}