Is there a difference between continuous light and still life taken by flash?

There is a difference, because the flash is powerful and can provide high illumination instantly, which is very helpful for some items that need to be "penetrated", such as displaying some translucent items.

For the learning stage, the use of constant light source is very helpful for the learning and utilization of light ratio, which is equivalent to the modeling light of flash lamp.

On the other hand, if flash and continuous light are mixed, it is better to use three kinds of continuous light.