Editing Rich client (section)

== Introduction ==
The designer of a client–server application decides which parts of the task should be executed on the client, and which on the server.  This decision can crucially affect the cost of clients and servers, the robustness and security of the application as a whole, and the flexibility of the design for later modification or [[porting]].

The characteristics of the user interface often force the decision on a designer.  For instance, a drawing package could require the download of an initial image from a server, and allow all edits to be made locally, returning the revised drawing to the server upon completion.  This would require a rich client and might be characterised by a long delay to start and stop (while a whole complex drawing was transferred), but quick to edit.

Conversely, a thin client could download just the visible parts of the drawing at the beginning and send each change back to the server to update the drawing.  This might be characterised by a short start-up time, but a tediously slow editing process.

=== History ===
The original server clients were simple text display terminals including [[Wyse]] [[Computer terminal|VDU]]s, and rich clients were generally not used until the increase in PC usage. The original driving force for thin client computing was often cost; at a time when CRT terminals and PCs were relatively expensive, the thin-client–server architecture enabled the ability to deploy the desktop computing experience to many users. As PC prices decreased, combined with a drop in software licensing costs, rich client–server architectures became more attractive. For users, the rich client device provided a more-responsive platform and often an improved [[graphical user interface|graphical user interface (GUI)]] than what could be achieved in a thin client environment.{{Citation needed|date=May 2020}} In more recent years, the Internet has tended to drive the thin client model despite the prodigious processing power that a modern PC has available.{{Citation needed|date=June 2008}}

=== Centrally hosted rich client applications ===
Probably the thinnest clients, sometimes called "ultra thin," are [[remote desktop]] applications, e.g. the [[Citrix]] products, and [[Microsoft]]'s [[Remote Desktop Services]], which effectively allow applications to run on a centrally-hosted virtual PC and copy keystrokes and screen images between the local PC and the virtual PC. These ultra-thin clients are often used to make available complex or data-hungry applications that have been implemented as rich clients but the true client is hosted very near to the network server.{{Citation needed|date=June 2008}}