Terminology in a very simple way to understand:
Rule of people, it is a way to stop ruler to abuse their power by ordinary people. Democracy is a container which can hold many different ideas(such as nationalist, komunist, republican and so on) and political differences and in stead of getting gun and shooting each other based on political differences and become a ruler, the differences is settled on ballot boxes (civilized).
Democracy is not an political party, it is just a container to hold all different political views. It is an achievement by human being like many other achievements which we enjoy such as airplane, medicines and many more.