Please shed some light???

Hello! I have a few YouTube videos that I watch/listen to now and then, but all of a sudden I can't do so and I get the following message:

Hello, you either have JavaScript turned off or an old version of Macromedia's Flash Player. Get the latest flash player.
Being a moron where computers are concerned, can you please tell me what IS JavaScript? I know I have Java installed, as one or two news sites that I visit require it, but JavaScript? I have no idea. Is there some way I can check to verify whether I have it installed? And if I do have it, but turned off, how do I turn it on again? Or if I haven't got it, where do I download it, as well as Macromedia?

Sorry to pester you with these seemingly silly questions, but I really am in the dark. Will appreciate your input! Thanks!

 

Chances are that it's the flash player...try downloading it and see if you still get that message. PS it is now Adobe flash player

http://www.majorgeeks.com/Adobe_Flash_Player_IE_AOL_d5163.html