Knowledge Points (KP) are a special kind of currency. They are assembled in the Knowledge Point Bar on top of the Interface. You can acquire them on several occasions and they have many uses.
Acquiring Knowledge Points
Knowledge Points are generated at a rate of one every hour until the Knowledge Point Bar is full. Normally that will be at 10 Knowledge Points. You can extend this number to 20 by using the Enchantment "Inspiring Meditation". You can purchase Knowledge Points for Coins or your Boosted Goods by clicking the right beside the Knowledge Point Bar You can also get Knowledge Points as rewards from Tournaments, for finishing encounters in Provinces on the World Map or as rewards from spending your knowledge points in Ancient Wonders of other players. These rewards will be added to the Knowledge Point Bar even if it is completely filled. Events will give Ancient Knowledge Instants as rewards, that will add a certain number of Knowledge Points to an Ancient Wonder.
Using Knowledge Points
Knowledge Points have several uses. You can use them in the Research Menu to advance Technologies. Or you can spend them in Ancient Wonders, both your own and those of other players. If you have an Ancient Knowledge Instant, you can use it to insert the given amount of Knowlegde Points to your or other players Ancient Wonders.