What is the difference between PUT and PATCH in REST APIs?

• PUT: Replaces the entire resource with the data sent.
• If a field is missing in the request, it may get erased.
• Idempotent (same request repeated yields same result).
• PATCH: Applies partial updates to the resource.
• Only changes the fields specified.
• Not necessarily idempotent.

Example: Updating user email.

• PUT /users/1 with { "name": "Alice" } replaces whole user — email might

get removed.

• PATCH /users/1 with { "email": "new@example.com" } updates just the

email.