@abhibeckert@lemmy.world may be correct if you're talking about the manufacturer's warranty.
Under Australian Consumer Law, however, the statutory warranty does indeed reset when a replacement is received. Note, though, that you are entitled to your choice of a refund or "replacement of the same type of product". This gets around abhi's concern that the product may have an underlying design flaw that would mean replacing with the exact same product would end up having the effect of giving you free replacements for life. Instead, they can give you a similar product—most likely the same manufacturer's newer model.