Hi, I am a newbie for Scratch development and I don't have a clear idea about the difference between ScratchX extensions and Scratch Flash extensions. If someone can someone can explain it here, it would be a big help for me.

Also,
Can I use JS extensions which is used in ScratchX in Scratch Flash ?
Also if can, how can I debug those in Flash environment ?

Thank you.

You don't use experimental extensions in the Scratch editor*, you only use them in ScratchX. Also, ScratchX uses Flash too and basically is the same as the Scratch online editor.

*some people run extensions in the Scratch editor by pasting the whole extension code in the web console but I don't