What does continuous autofocus mean in Canon 90D settings?

That is, once in focus, the camera's focusing system will continue to track the focus, which is suitable for capturing moving people and animals.

However, we must pay attention to one thing, that is, continuous focus, no focus prompt tone, once out of focus, the shutter will be released, and it may take out-of-focus photos. The single focus, not only has the focus prompt sound, but also the out-of-focus shutter does not release.

We should use the focusing method reasonably in different occasions and understand its characteristics.