"software": how does it really work?

[andrea]

Hi,

I'm on Fedora 22 default gnome desktop.

I've got a few questions about "software"

1) how does it integrate with dnf? for instance if I do "dnf history" I do not see any of the 
transactions done with the "software" app.

2) do "software" and dnf have the same source? there are packages available only via dnf.

3) when I check for updates "software" most of the times says

"up to date - nothing to do - checked at XX:YY" (maybe 2 minutes ago)

Then I force it to check and often it finds something to update. Once it is a coincidence, but is it 
possible that so often updates are published just in the few minutes between the automatic and 
manual check?

Andrea