To start with, a framework is more like a tool box that has the tools to accomplish basic tasks e.g A carpenter's toolbox would contain hammer, nails, etc.
Laravel is a PHP framework that makes you app development simple and faster, it comes with the basic things you need to build your web app and more e.g:
more at laravel.com
So it makes you write less code than you would writing your web app from the scratch, so you focus on your app logic plus it's easy to learn.
I hope this helps