Daniel Hanna wrote in
home.com.au:

In m Anne Lurie wrote:
To the best of my knowledge, hydrogen peroxide is NOT synonymous with
hydrogen dioxide -- any more than carbon monoxide can be equated
with carbon dioxide!!!

Anne, you're right. Hydrogen dioxide is simply water - H20. Hydrogen
PERoxide is H202, i.e. one hydrogen per each oxygen atom. It
biodegrades to water plus oxygen quite easily.

If you want to know more, follow this boring link :-)
http://www.h2o2.com/intro/overview.html

Water is not hydrogen dioxide - H2O has only a single oxygen - dioxide
would inidcate 2 oxygens.

Hydrogen dioxide is the same as hydrogen peroxide - peroxide indicates that
the oxygens are bound to each other in an O-O bond - just a fancier way of
labeling it in hopes that the shopper won't realize they can get it a
Walgreens for a tenth of the cost.