From: Political Science Degree blog by Phillip Donavan:
When we speak of political systems, it’s difficult to determine what the most common types are. After all, many political systems are similar, or have similar roots. Many countries actually have republics of some kind — variants of democracy. As you study political science, it can be helpful to understand some of the most common types of political systems from around the world.
Understanding different political systems is important. Each political system has its advantages and disadvantages. It is worth considering the merits of other political systems, and perhaps incorporating some of the ideas into your own system. Some of the five more common political systems around the world include: