Definition from wikipedia:
that means BlazeDS acts like a server like Apache?
What is back-end distributed data?
Basically, is you use straight PHP, then you do everything yourself, unless you are using a framework written in PHP like AMFPHP.
So with PHP you typically use Flex HTTPService controls to call your PHP scripts, and the communication is one-way, you call the script and handle the returned data.
With BlazeDS and AMFPHP, you can use Flex RemoteObject controls for two-way "server push" functionality, like a stock ticker updating automatically without the user doing anything if the price of a stock goes up.
Backend distributed data just means you have the data elsewhere (not on the user's machine), and it could be distributed (on serveral servers).
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