Quote: "1) What's the difference between alpha testers and beta testers"
I'll apply this more to all software (not only games)
Alpha - Early testing of a software, used to spot bugs in the basic engine and such. Some small features added here and there, but its like a First Draft in writing. Usually done In-House, instead of public or people outside the Dev-House.
Beta - Engine testing done, now time to test some real features. This usually has many updates as features are added and taken due to suggestions from the testers. The Engine still in a rough form at the beggining, takes shape and grows through out. Alot of times, Betas will be done somewhat out of house, and will involve alot more then the Alpha test. Sometimes the Dev's will look to Public tests and collect information and bugs through that. This Stage usually last's several months.
Quote: "2) When does a game go from being a beta to a demo
"
Beta usually has nothing to do with the Demo. A demo is alot of times released before a product to Show off the engine and generate interest. Though in the later years, we have seen less demos before release, and they have been getting released well after the products release, to boost sales back up.
Quote: "3) what do those version numbers mean. How do I know my demo is demo version 1.1 or 2 or 2.0 etc etc."
Version numbers are used to identify, well, what version you have. As the program gets upgraded you add a new version number. Alot of times, its to the Dev's discression what number they are gonna use. To find out what version, alot of times it'll be in a read-me, a help, or maybe just the corner of the screen in the game.
Hope I helped.
Eric
If you love someone, set them free; If they come home, set them on fire.