Question

the bleaching action of hydrogen peroxide is due to oxidation or reduction

Answer 1

Bleaching action of hydrogen peroxide:
It acts as bleaching agent due to the release of nascent oxygen.
H₂O2 $\to$ H₂O + O
Thus, the bleaching action of hydrogen peroxide is permanent and it is due to oxidation. It oxidises the colouring matter to a colourless product.
Colouring matter + O $\to$ Colourless matter.