What is the difference between a restrictive and a non-restrictive relative clause?

Relative Clauses Questions

What is the difference between a restrictive and a non-restrictive relative clause?

A restrictive relative clause provides essential information about the noun it modifies and cannot be removed without changing the meaning of the sentence. It is usually not separated by commas.

A non-restrictive relative clause provides additional, non-essential information about the noun it modifies and can be removed without changing the meaning of the sentence. It is usually separated by commas.