My favorite benefit is that you can work with Docker on your development machine (setup and configure all your software's) and then move the exact environment to the hosting server. This is not possible (or at least very not recommended) with Virtual Machines.
My second favorite benefit is that you can break anything without worrying about it, no matter what you do wrong with your Virtual Container (Docker) it will not affect anything else (any other software) because each software runs on a different Container. You can easily destroy your corrupted container and build a new one to mess with it again :)
If it happens and you use PHP (with Laravel) check out this cool project LaraDock. It helps you get up and running with Docker in less than 5 seconds! (it's like Laravel Homestead but for Docker).