Enlightments are oart of Sharl Han. They're explained on the infantry cards. Basically things can grab enlightments which other models grant as an aura. This is done when they activate or when attacked.
Insights are granted to models in a combined activation when they have the same type as the leader issuing the activation.
Dave you are referring to inspires not insights. Insights are the auras that you can choose from with the Enlightenment ability.