This host runs Ubuntu 24.04. Prove which parts an Alpine container shares with it and which parts it does not.

Start with the kernel, on the host and in a container:

uname -r
docker run --rm alpine:3.20 uname -r

Now compare the operating system files:

grep PRETTY /etc/os-release
docker run --rm alpine:3.20 grep PRETTY /etc/os-release

And the hostname:

hostname
docker run --rm alpine:3.20 hostname

Save the container's full release file on the host, then read it:

docker run --rm alpine:3.20 cat /etc/os-release > ~/alpine-os-release.txt
cat ~/alpine-os-release.txt

Same kernel, different filesystem: that is the difference between a container and a VM.