Civics are a key part for Civilizations in Empires & Emperors. Whenever you've upgraded from a City-State to a Civilization you are allowed to start studying Civics.
To study a Civic you require some money to start it and it takes Culture to process to finish it.
Civics are the same as technologies, but instead of Science they take Culture to process. The other difference is that Civics do not have a set culture cost, instead they start to cost more culture if you have studied more civics.
On the Civic Tree you see that each tier has a requirement of completed Civics.
You can only study 4 Civics per tier, and in order to progress towards the next tier you need to have at least 3 civics studied in the previous tier.
The requirement to study a civics can be found below.
Whenever you've started studying a Civic it takes a specific culture to complete it. Every minute it adds culture to the civic and eventually it'll be finished. Every town's culture ouput is added so it's not only your capitol doing all the work for civics.
To calculate the culture cost you have to follow this formula;
Rate = 1 -(Civilizations with civic unlocked * 0.03) + (Amount of Towns in Civ * 0.1)
Culture cost = ((Civics completed + 1) * 9000) * rate