1. The degree of fermentation is different: black tea belongs to fully fermented tea, while black oolong tea belongs to semi-fermented tea. The degree of fermentation of black tea is deeper than that of black oolong tea, so the color is darker and the taste is stronger.

2. Different processing methods: black tea is made through the steps of kneading, fermentation and drying, while black oolong tea is made through the steps of shaking, kneading, fermentation and baking.

3. The taste is different: black tea has a strong flavor, and has obvious malt and fruity aroma, and the taste will have a sweet feeling. The taste of black oolong tea is lighter than black tea, but has a unique floral and fruity aroma, and with some acidic flavor.

4. Different brewing methods: Generally speaking, black tea is brewed with boiling water for a shorter period of time, while black oolong tea is brewed with water at about 90℃ for a longer period of time. In addition, black oolong tea is steeped more often than black tea because black oolong tea contains more aromatic components, so there is still a lot of flavor to be extracted after each steeping.

Overall, black tea is stronger and heavier than black oolong tea, making it suitable for pairing with oily foods. Black oolong tea, on the other hand, is lighter and softer in flavor, making it suitable for pairing with lighter foods.