Here is a take on a list of terms.
[HTTP] request: [We at least need a way to log requests made by a user-agent.]
[HTTP] response: In HTTP, the combination of the status code and the entities. [JAR: An HTTP response can also include response-headers that are not entity-headers...]
Status: On hold
Agent: @@?? [Are there agents that aren't user agents? Thinking in the large sense of the term, even non-web agents.] [Tim: Agent owns a domain name, agent runs a server, agent runs a browser, agent sends a request.] [Is there a foaf:Agent ?]
Protocol: A convention for transmitting information between two or more agents. [Let us pretend for now that either there is no need to distinguish between protocols, or that http is the only protocol, or that we are not talking about any other protocols.]
Status: Not yet evaluated
Payload: The information transmitted by a protocol. [Maybe payload = message. Is the status code part of the payload? Is a payload different from an entity?]
Client-Server Architecture: protocols take the form of a request for information and a response with information.
Client: The agent that is requesting information. In the context of the Web, called a user-agent.
Server: The agent that is responding to the request.
HTTP: A protocol originally purposed for the transfer of hypertext documents, although its now ubiquitous nature often lets it be used for the transfer of almost any string of bits.
User-agent. A client in the context of the Web.
Method : A request for a certain type of information from a user-agent
headers: In HTTP, the part of the method that specify some information that may be of used by the server to determine the response or that specifies to the client information about the response.
request: the method used by the agent and the headers, along with a blank line and an optional message body.
content types: The types of encodings that can be explicitly given in a response or request in HTTP
Internet Media Type: A generalization of content types to any Internet protocol. It consists of a two-part scheme (separated by the '\') that separates the type and a subtype of an encoding.
The World Wide Web: @@ An information space in which the items of interest, referred to as resources, are identified by global identifiers called Uniform Resource Identifiers (URI)
Message: @@ things that have headers and optional content, etc.
entity: the information transferred as the payload of a request or response
@@ An entity consists of metainformation in the form of entity-header fields and content in the form of an entity-body (rfc2616)
status code: which is one of a finite number of codes gives the user-agent information about the server response itself.
Content Negotiation: a mechanism defined in a protocol that makes it possible to respond to a request with different representations of the same resource depending on the preference of the user-agent.
Web representation: the particular encoding of the content given by a resource.
(so are representations ONLY in response? i don't think so...)
resource: the content of any information capable of having identity. A resource may have a URI.
state: information about a resource that is not given as part of its identity, so it is information that may change over time.
cache: when a user-agent has a local copy of a Web representation that it accesses in response to a request rather than getting a Web representation from the server itself.
proxy: a cache that is not stored on the user-agent itself, but are shared among multiple user-agents by a server or group of servers}.