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:
GET a representation of the target resource;
HEAD the same representation as GET, but without the representation data;
POST a representation of the status or results obtained from the action;
PUT or DELETE a representation of the status of the action;
OPTIONS a representation of the communication options;
TRACE a representation of the request message as received by the final server.
Aside from responses to CONNECT, a 200 response always has a payload, although 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 header section of the 200 response.
A 200 response is cacheable by default; that is, unless otherwise indicated by the method definition or explicit cache controls.