Why does yum updateinfo not show all updates?

Why does yum updateinfo not show all updates? It gives different info by design.

It looks like you submitted yum updateinfo summary updates, which shows advisory information, as is apparent by looking at the output and according to man yum:

* updates Is used to display information about advisories for packages that can be updated. This is the default.

On the other hand, according to its documentation, yum check-update does this:

This command allows you to determine whether any updates are available for your installed packages. yum returns a list of all package updates from all repositories if any are available.