Basurl is commented

I have the following config in fedora.repo:

[fedora]
name=Fedora $releasever - $basearch
#baseurl=http://download.example/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/
metalink=https://mirrors.fedoraproject.org/metalink?repo=fedora-$releasever&arch=$basearch
enabled=1
countme=1
metadata_expire=7d
repo_gpgcheck=0
type=rpm
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch
skip_if_unavailable=False

But when I use yum command , it’s work fine.
What’s use of baseurl? and what’s difference with metalink?
Why baseurl is configured with example in host ?

I assume it’s an example of the string you would employ if you wanted to link directly to a source instead of using a metalink mirror that would pick a random mirror. So you keep the baseurl example link commented out but create a new baseurl with a direct link replacing download and example with domain-name and tld. For example I’m in the UK, so always use Mirrorservice for my downloads. If I was making a baseurl I would use https://mirrorservice.org/sites/dl.fedoraproject.org/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/