What is the difference between multi-point focusing and single-point focusing in photography?

The dynamic area is that the computer helps you choose the focus, and within the dynamic range you set, the computer helps you choose. And it has the ability to chase coke. Single-point focusing is to artificially determine which focusing point to use. The former refers to the choice of focusing, and af-c is the focusing mode. There are only three modes. Press the shutter once to focus, even if the object moves the shutter. Then you can't shoot without focusing, even if you press the shutter. One is the continuous focusing of the computer, which is needed whenever the shutter is pressed, such as when people move. Finally, what kind of mode is the computer? Naturally, under normal circumstances, we will definitely use this. Convenient. In general, it is single-point focusing-the computer automatically selects servo, still life is good, and single servo. Moving object, dynamic mode focusing+continuous servo. (Continuous servo consumes power, and the accuracy is not as good as that of single servo if it is stationary.)