How to understand the echoing relationship of calligraphy

The echoing relationship of calligraphy should refer to the coherent relationship between strokes and between the two words. In the process of writing a word, the trajectory of the previous stroke points to the starting point of the next stroke. The same is true between two words. So as to form a natural and smooth echo relationship. It seems to be a real feeling.

This is only for running script and cursive script, regular script and official script, and there is no such problem.