What is Java Script?

There is a place to turn off my Java Script in my iPad.  When I turned it off, I saw someone put some information of PayPal in my redbubble account and which was taken out right away to verify it.  But I couldn't see the page of PayPal to make sure whose PayPal account is.  I saved again my bank account and redbubble sent me to my email which mentioned if I didn't change my bank info, let them know.  I saved once but this mail was sent twice.  I guess because hackers took it right away while I am checking.  I tried to throw away that emails cause I don't want them to say that no one changed payment information.  But I couldn't find these emails from my trash right after I threw away with other junk mails though I could see other junks.  They hide it right away.  And also this blog, if I turn off Java, then I cannot see my log in page neither my comment which I put to check in.

The problem is that they are doing this while I am typing right now seeing what I do at the same time.  And I cannot find my mail and I am sure they put their PayPal account which they use my name will be back right after I am away from my account.