Unbound is a validating, recursive, and caching DNS resolver. It can be used to create your own recursive DNS-Server at home. You can use Unbound for services such as Pi-Hole (Here is a tutorial how to configure Pi-Hole with Unbound: https://www.youtube.com/watch?v=FnFtWsZ8IP0&t=695s) or you can create custom DNS Records for your local network.