The request has succeeded.
The payload sent in a 200 response depends on the request method. For the methods defined by this specification, the intended meaning of the payload can be summarized as:
GETa representation of the target resource
HEADthe same representation as
GET, but without the representation data
POSTa representation of the status of, or results obtained from, the action;
DELETEa representation of the status of the action;
OPTIONSa representation of the communications options;
TRACEa representation of the request message as received by the end server.
Aside from responses to CONNECT, a 200 response always has a payload, though an origin server MAY generate a payload body of zero length. If no payload is desired, an origin server ought to send 204 No Content instead. For CONNECT, no payload is allowed because the successful result is a tunnel, which begins immediately after the 200 response header section.
A 200 response is cacheable by default; i.e., unless otherwise indicated by the method definition or explicit cache controls1.
200 Code References
.NET HTTP Status Enum
Rust HTTP Status Constant
Rails HTTP Status Symbol
Go HTTP Status Constant
Symfony HTTP Status Constant
Python2 HTTP Status Constant
Python3+ HTTP Status Constant
Python3.5+ HTTP Status Constant