What are the 4 levels of feudalism?

The 4 levels of feudalism are as follows:

• Monarchs 
• Nobles 
• Knights
• Peasants/Serf

Feudalism was a system in which people were given land and protection by people of higher rank, and worked and fought for them in return. 

For further reading check the following articles:

• Portuguese India
• British Raj
• Dutch Colonialism in India