Which HTTP method is used to update data on a server?

The HTTP method used to update data on a server is PUT. This method is specifically designed to send data to the server to update an existing resource or create a new resource if it does not already exist. When using PUT, the client typically includes the entire representation of the resource, and if the resource specified by the URL already exists, it will be replaced with the data provided in the request.

For example, if you have a resource representing a user with a specific ID, and you want to update that user's information, you would use a PUT request to send the updated user information to the server. This would lead to the existing resource being updated with the new details.

In contrast, the GET method is used to retrieve data from the server without making any changes, while POST is typically utilized for creating new resources rather than updating existing ones. The DELETE method serves to remove resources from the server, rather than modify them. Thus, PUT is the appropriate choice for updating existing data.