Whats the basic difference between Flash version and also other Macromedia software?

Whats the basic difference between Flash version and also other Macromedia software?
I would like to ask whats the difference between Flash MX, Flash MX 2004 “Professional” and Flash 5? Is there a specific version for specific users/developers? Ive known flash for sometime now but I wasnt able to get updated anymore for almost four or five years now… I have basic know-how in flash and right now Im going back and learning flash again because my new job requires it…

I was wondering what Flash MX 2004 Professional has compared to MX and Flash 5? and is Flash MX 2004 just the “latest” version of flash or is it just another “version specific release”? Also is there a specific version of flash for specific users/developer i.e. “you should use flash 5 or mx for newbies learning flash/animators or you should use flash mx 2004 if your a hardcore developer/animator” Or any version of flash will do for as long as it is a “new release”?

And lastly what version would you suggest for a returning flash enthusiast? if ever there is a specific version for specific users? or should I use MX 2004 instead? And what is the latest version release of Flash?

This also goes to all macromedia application specially dreamweaver.