You mean JapaneseJJ, or BrazilianJJ?
JapaneseJJ has Judo throws but is more standup and rounded as far as tools to use and techniques available. The difference is the way it is usually trained. Judo is trained with a sporting concept and allows players to practice their throws full force with little risk of injury (they say that anyway, Judo still hurts).
Compared to BJJ, which originated from Judo, they are basically the same with BJJ concentrating more on matwork and Judo more on throws (usually).
They are just basic explanations...a little web research will turn up lots of info about all 3 (JJJ, BJJ, and Judo).