Flash is a platform (aka program type thing) which enables animation, videos and interactivity (and a lot of time games).
Good example is when you go to a website and on the splash page there appears to be a movie or presentation - that is usually either Flash or HTML5.
Flash has many good features and is used a lot but the problem is it is HUGE and usually the something running is Flash is rather large. This is a problem int he mobile space where memory is a premium. The problem with HTML5, in my opinion is that is it not as feature rich there for it some what limits what you can do with the development.
I know there is probably someone on YT who is far more technical and can explain it far better but I hope this helps.
I will add I have had an IPad since their introduction and I cannot remember the last time I had a problem with using it because of lack of Flash. In the beginning yes but I think there is more and more migration to HTML 5.
__________________ Cheryl,Mom to  SophieKate |