> why you need DNS for at server? just use hosts file.

IP's can change without warning.

You have to go back five decades if you want to use a host file. My point is that cache and making are the three hard things in computer science DNS has had both problems several times. I choose DNS over hosts files every time.

EDIT I might be off by one here.

interesting.

But it's not an issue at all, and it provides a convenience that can be depended on by a lot of your dependencies.

Code may use domains instead of ip addresses (which provides resiliency), package managers like apt depend on domains. And so on.

clusters and other load-balanced workloads. who wants to maintain hosts files across a fleet of containers or multiregion load-balanced situations?