When you heal with Greater Heal, the cooldown of your Inner Focus is reduced by 5 sec.
When you Smite, the cooldown of your Penance is reduced by 0.5 sec.
Train of Thought is a passive priest ability learned at level 78 for those with the Discipline specialization. It reduces the cooldown of two spells, [Inner Focus] and [Penance], through the use of two abilities ([Greater Heal] and [Smite] respectively).