Village level info
Each village has 5 different tiers. Every time you upgrade it, it generates units faster, gets more defense, and has a higher unit capacity. The cost and duration it takes to upgrade villages also increase as the level increases:
The higher the level, the more defense the village will have and the faster it will produce units, making it easier to defend. It is impossible to upgrade to a tier 5 village, however some maps allow you to start with a tier 5 village.