Presence of the Master

Ok what does it mean? Cooldown?

yes it reduces the cooldown to your summoner spells by 15%

This only affects SUMMONER spells, i.e. Flash, Ghost, etc., and not regular spells such as your Q W E and R skills. This should be taken into consideration when going into the utility tree.

I for one have thought for long that it did actually affect your champion's spells...

Most people think it does affect champion abilities. But if you think about it 15% on your abilities from lvl 1 would be insane.
Gotta use offense tree for ability cdr.

Utility: Intelligence
Reduces your champion's cooldowns by {2/4/6}%

You can use Offensive and/or Utility to get Ability CDR

Does this not work on some spells?like revive becuase i couldnt see a difference when playing as utility and having revive

It applies the CDR AFTER YOU CAST THE SPELL. So the coldown looks the same, they just chop off time acordingly.

I don't care about my rep, but you can +rep if you want to.