HTTP Success Codes : & REST API Headers

When a request is successful, the response header contains an HTTP code, and the
response body contains a Boolean success value.
200 : The request has been successfully processed.
201 : The request has been successfully processed and the
resource has been created.
204 : The request has been successfully processed, but no content
is returned in the response body. This code is returned after a
resource is successfully deleted.

HTTP Methods
REST API supports the following HTTP methods:
GET : Retrieves information, such as basic resource summary
information.
HEAD : Retrieves resource metadata.
PATCH:  Updates a record.
POST : Creates a new object.
DELETE : Deletes a record

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REST API Headers:
REST API supports the following headers:


Header Description Example:

Content-Type: Specifies whether the request is formatted as JSON or XML. Content-Type: application/json

Authorization :Used to authenticate the request. Authorization: OAuth sessionId
X-Pretty-Print Formats the response in a more readable format with line breaks and
indentation.

X-PrettyPrint:1: Formats the response in a more readable format with line breaks and
indentation.

Accept :Indicates the resource format which can be either JSON or XML. Accept: application/xml

X-Sfdc-PackageVersion : Specifies the package version under which context an API call is made. x-sfdc-packageversion-namespace: 2.0