Knowledge reflects how advanced your civilization is.
There are 5 knowledge branches in game:
- Engineering: How advanced buildings can you build and how much can you upgrade them
- Food production: How far can you develop your food producing rural regions
- Humanitarian: How well you can spread the ideas at your population and other nations' citizens
- Military: Your strength in military conflicts and your logistics abilities
- Maritime: Oversees exploration and expansion
The activities of your citizens and the surrounding environment affects how your knowledge progress along these branches and how efficient your progress along each branch will be.