The technologies you can learn are broken into three different tech trees, each with their own focus and prerequisites. Which trees you decide to invest in is up to you but keep in mind that you can only learn one technology at a time.
The Civilization tree is focused on improving your nation’s economy and infrastructure. Here you will find dozens of improvements that increase city Production, food supplies, Research and Gildar income. In addition, Civilization is the tree of diplomacy, improving your options when dealing with other nations and helping your recruit units from the wild.
The Warfare tree is designed to help your efforts with trained units and Champions. It unlocks new training techniques and improvements that boost your trained units. All of your non-magical equipment is unlocked from Warfare including multiple varieties of armor, weapons, mounts and more. While magical equipment may be stronger in many cases, equipment unlocked in the Warfare tree has the advantage of only requiring metal and being easier to produce en masse.
The Magic tree is built on the unlocking of magical spells, equipment and improvements. It will allow you to build and purchase the most powerful weapons, armor and accessories for your units with the enough Crystal and Gildar. Along with magical equipment, the Magic tree is the ultimate tree for Champions. Through it you can recruit higher level Champions in the world as well as provide them with new spells.