I have just started getting interested in Flash, and up until now I was not aware of Flex and how it is similar and different from Flash. I did some looking around, looked up flash vs. flex on google, and read the wikipedias, but I still can't get the why you use one or the other. The best I got was that Flex is for writing applications, and Flash is used for web development. But then I also read that you use Flash for games. Wouldn't a game be more like an application than standard application development? What do people mean when they say Flex is for application development and Flash is not? I want to develop games on the Flash platform, but I also want to use AS3 extensively (I have a programming background, not a design background), so should I use Flex or Flash? (I am learning the design side, but I figure I would not be making my own assets in a serious project) Where do the two fit in together, if at all? Can you make use of both Flex and Flash in the same project, and is there a benefit? Sorry about all the questions, but as you can see I am thoroughly confused now and worried that I may spend my time learning the wrong tool for what I want to do. Thanks for any and all input!

Flex is for building rich web applications, and is almost entirely code based. Imagine Flash without the editor. If your a beginner, I would just stick with flash for a few years (paying particularly close attention to actionscript) before you try to tackle this baby. You could make applications just as easily in Flash, so don't sweat it. Flex offers greater flexability (hence the name) in creating more robust components (basically by extending what's already there) based on the AS lib, particularly in aspects of animation and databases.

I appreciate the fast response. That makes more sense now.

Flash CS and Flex are tools to create the same final product: flash files.

Now, some developers and artists might be more comfortable with one tool or another.... so choosing between flash or flex is mostly about in which tool are you more comfortable.

Flash CS is mostly for artists and designers that want to create flash files with a WYSIWYG editor, without having to deal with learning a programming language, or having to touch it minimally.

The main advantage of Flash CS is that you can have a nice, running flash in a very short time, but it will look like most flash movies you see arround; a movie flic.

Flex is mostly for coders, and almost everything is done by writing code, so it's intended for software developers that are used to development environments like Visual Studio, Eclipse, etc

The main advantage is that you program in ActionScript3, which is becoming a first class programming language, and the disadvantage is that you really have to master the language to start having simple results.

Overall, Flex is probably much more powerful, also much more complex, and with much longer development cycles.

If you want to be really hardcore you could check out Adobe Alchemy. It allows you to write Native C/C++ and compile it to flash, with a minimum amount of AS3 glue code. It works great, and runs much much faster then writing the same thing in pure Action script.

http://labs.adobe.com/technologies/alchemy/