Differences between 'traditional' Henna and Jagua Henna are:
Traditional Henna will dye the skin red/brown while Jagua Henna will dye the skin dark blue/black.
There is no such thing as safe black 'traditional' Henna but Jagua Henna can safely provide a blue/black color.
Traditional Henna has been used for centuries throughout the Middle-East and Asia.
Jagua has been used for centuries by the local tribes of Central and South America.