Why was Germany divided into East and West Germany?

In the period from 1949 till 1990, Germany was split in east and west. Why was there a West and East Germany created? In this video I will explain how and why it came to that split.

Link to the Cecilienhof Palace in Potsdam:
https://www.spsg.de/en/palaces-garden...


Credits:
• Marshall plan picture: E. Spreckmeester, published Economic Cooperation Administration - Source, Publiek domein, https://commons.wikimedia.org/w/index...
• Hier hilft der Marshall plan foto: Par Bundesarchiv, Bild 183-20671-0014 / CC-BY-SA 3.0, CC BY-SA 3.0 de, https://commons.wikimedia.org/w/index...
• D-Mark: By National Museum of American History - Image by Godot13, Public Domain, https://commons.wikimedia.org/w/index...
• 100 DM: Alliierte Militärbehörde in Deutschland, Public domain, via Wikimedia Commons