The problem is, there's a lot of them.

There are reserved words of Javascript, and then there's reserved words of the browser itself (more accurately, it's "DOM"). Most confusingly, the details of that list depends on which browser you're using - Chrome, Firefox, Safari, or Internet Explorer. They're mostly the same, but each has a few extras thrown in.

You can find a comprehensive list here. Don't try to memorize them, just have a look and get an idea of the flavour.

And do your best to avoid naming your variables or functions these words.

If ever something totally crazy is happening, maybe you've had a collision with a reserved word.