Butter is separated from milk by - 

Explanation:

• Butter is separated from milk through a process called churning.
• Churning involves agitating or beating the cream that is obtained from milk.
• During this process, the fat globules in the cream clump together, forming butter.
• The remaining liquid is known as buttermilk.
• The traditional method involves allowing the cream to naturally separate from milk, and then the cream is churned to produce butter.
• In modern dairy processing, the separation of cream from milk is often done mechanically using centrifugal force in a machine called a cream separator.
• Once the cream is separated, it can be churned to produce butter