Harvesting from Roy's paper

Roy T. Fielding and Richard N. Taylor.
Principled Design of the Modern Web Architecture.
ACM Transactions on Internet Technology (TOIT), 2002.
http://www.isr.uci.edu/~taylor/documents/2002-REST-TOIT.pdf

... allowing a user to progress through the application by selecting a
link or submitting a short data-entry form, with each action resulting
in a transition to the next state of the application by transferring a
representation of that state to the user.

    [A representation is of a state.]

REST components communicate by transferring a representation of the
data ...

    [A representation is of data.]

Finally, it allows an author to reference the concept rather than some
singular representation of that concept, thus removing the need to
change all existing links whenever the representation changes.

    [A representation is of a concept.]

Depending on the message control data, a given representation may
indicate the current state of the requested resource, the desired
state for the requested resource, or the value of some other resource,
such as a representation of the input data within a client’s query
form, or a representation of some error condition for a response.

    [A representation *indicates* a state.]

... the specification of Web addresses also defines the scope and semantics
of what we mean by resource, which has changed since the early Web
architecture. REST was used to define the term resource for the URI
standard [Berners-Lee et al. 1998], as well as the overall semantics
of the generic interface for manipulating resources via their
representations.

    [A resource can be manipulated via a machine interface.]

A resource does not always map to a singular file, but all resources
that are not static are derived from some other resources, and by
following the derivation tree an author can eventually find *all of the
source resources that must be edited* in order to modify the
representation of a resource.  [emphasis JAR's]

    [A resource is derived from editable sources.]

Semantics are a byproduct of the act of
assigning resource identifiers and populating those resources with
representations. At no time whatsoever do the server or client
software need to know or understand the meaning of a URI—they merely
act as a conduit through which the creator of a resource (a human
naming authority) can associate representations with the semantics
identified by the URI. In other words, *there are no resources on the
server*; just mechanisms that supply answers across an abstract
interface defined by resources.  [emphasis JAR's]

    [Resources do not reside on servers.]

Received on Monday, 7 March 2011 12:54:36 UTC