What does Hydrogen Peroxide do?

I've seen it mentioned in a few threads that people have used H2O2 on their plants, but I've never seen an explination. What does the peroxide do for the plant?

well.... if you look at the chemical makeup it helps. As h2o2 it kills most known pathogens and breaks down to h2o (water) and o (oxygen), both of which your plants use. VV

its a great oxygen boost for hydro and soil setups. be careful using with organic ferts because h202 kills bacteria good and bad