Jrock is the
short version for "Japanese rock", which includes Visual Kei,
normal and alternative rock, but from Japanese bands. The term sometimes includes Japanese
metal bands (such as Maximum the Hormone), but it's more rarely seen.
The most popular Jrock band in
Japan is
SID, but the GazettE has a lot of fans outside the country. They play Visual Kei and DOES plays
normal rock in Japanese.