The short answer:
Wu-long / oolong / wu long / 烏龍茶 are all the same thing. It is the name of a Chinese tea category, in between green and black tea. Best drunk by itself (not with milk). Large full leaves. Some celebrities swear by it to keep them in shape.

The long answer:
Oolong is made from the same tea plant, Camellia Sinensis, like other tea (black/green/white). The differences between these tea types are based on their production methods. For Oolong tea, which is partially fermented (black tea is fully fermented and green tea is unfermented), the process is comparatively complex to other tea types and the degree of fermentation will determine whether the tea tastes stronger (like black tea) or lighter (like green tea).

Besides the rather addictive flavour and aroma only Oolong possesses, this category of tea has been reputed for digestion, skin toning, weight management and soothing allergic skin. Some celebrities swear by Wulong to keep them in shape.

There are 3 major oolong producing areas – Taiwan, Guangdong and Fujian.
Generally speaking, the beady ones tend to be more floral with softer flavour while the strippy Wulong (such as WuYi Shui Xian and Dan Chong) are bolder in taste.

Taiwanese oolong typically has lighter fermentation than Chinese ones, which means Taiwanese Wulong are greener in leaf colour and lighter in taste.

Check quality with your tea merchant as quality varies a lot in the market.

POPULAR OOLONG:

For us in Teas.com.au, White Dragon and Rose oolong are the most popular, but there are definitely devotees to Tie Guan Yin (Iron Goddess of Mercy) originated in FuJian, China.

Oolong typically yields about 3 good infusions and, like many good quality fine tea, it is particularly vulnerable to oxidation – so once brewed, use it quickly as oxygen can turn the tea smelling and tasting somewhat “vegie-like” after a while. (If you want to make chilled oolong, store the tea covered in the fridge when it is still tepid. Don’t let it cool uncovered.

Brewing oolong requires lot of room – we recommend the cup holder infuser for non-fuss brewing of oolong.

What is Wuyi Wulong – this is a bit of a general term, and some tea suppliers hype it up as “the weight loss tea”.

To be exact, we have Wuyi Shui Xian and the premium rock oolong called Wuyi Dao Hong Pao.
If caffeine is a concern, ditch the first quick infusion and start drinking from second brew onwards to reduce caffeine content.
Want to know oolong tea variants?
Teas.com.au – Oolong provides a great selection.