From this Clash of Kings map, you can decide who or what to attack. Once you secure your city's defenses and have a good army, you can launch an attack on the general map. Libraries, on the other hand, can provide longer-term benefits, like developing new technologies for your weaponry so you can fight your enemies with an advantage.
The barracks, for example, have a very direct purpose: they let you recruit soldiers. Each of these fulfills a specific objective that lets you advance in one way or another. In it, you can find lots of different structures like barracks, libraries, stables, farms, and mines. In Clash of Kings, the most important concept is that of the capital: the place where your empire begins.
Clash of Kings is a real-time strategy game where you can build your own city, recruit and train an army, and conquer all the nearby (and not so nearby) land to expand your empire.
