What's the difference between using a DllPlugin and simply splitting entry points (like app.js & vendors.js)?

Question

webpack

I have a config for a webpack, in which there are 2 entry points:
1) vendors, in which polyfills and third-party libraries are imported
2) app, containing the logic of the project itself
Everything works fine, when changes are made to the project files, app.js is quickly rebuilt, and when adding any new external dependency, I add a link to the added lib already in both files.
Please explain what the DllPlugin plugin is for, which, judging by the description (if I understood it correctly), is intended specifically for such scenarios.