What do dashed edges mean in Autodesk Maya 2017?

Question

3D

Do some faces become dashed when modeling and stitching in Autodesk Maya? What does this mean?
And why, when automatically merging half of the model (face) with a similar mirrored part with the Mirror command, the central edges along which the merging took place become sharp. how to avoid it? When smoothing or averaging vertices, the profile becomes too smooth.

Answer 1

most likely, the display of soften / harden edges is turned on. dotted respectively soft, sharp - hard