In Empires and Emperors, there are various wonders which give various buffs. Below you can press the structure you want to view and it'll give some more information about the wonder.
If you build 2 wonders in one town, you will gain a Wonder Combo Buff. They can be found by pressing here.
The Hammer Rates of each wonder is determined by the number of wonders you have inside your Civilization. For each wonder, you gain a 40% multiplicative penalty.