What does the lens 2x 1200 of Huawei p9 camera mean?

There are two rear12 megapixel black-and-white and color dual cameras on the P9 mobile phone, and the shooting effect is not as simple as shooting with two12 megapixel lenses. In the process of taking pictures, the dual cameras work at the same time, and the black-and-white lens captures details, making the image clearer; The color lens captures the color, making the color fuller, and its unique image synthesis algorithm makes the details and colors more vivid.