A Dual Camera is a conventional photographic tool that has a module with two lenses. The principle of such technology is standard: light passes through the lens, hits the sensor, and is read by the processor. Each of the two sensors works independently. That is, it creates a photograph independently. After that, the information is processed and combined into a single picture.
The second camera in the phone is most often used to create a bokeh effect, in which the photo’s background becomes blurred (see the term Autofocus). The resulting image can be compared to an image taken with a professional camera. The auxiliary module detects the position of the desired object, and all the blurring is performed already at the software level. Also, the second camera allows you to get more detailed photos. The first of the modules has a lower resolution but a larger aperture. And the second, on the contrary, has a higher resolution but a smaller aperture. This combination allows for getting better-quality images.
It is also possible to meet phones with dual cameras, supporting an optical zoom. This allows you to photograph objects at a great distance without losing quality. I also realized the function of additional focus allows you to highlight the desired details in the ready-made picture.