not a teacher
as I searched for the answer, I think that:
The "Seam" is the joint, the solder in a cloth, besides the "stitch" is a point,
a hole that is part of the seam.
You can say about a man injured: "he had ten stitches".
furthermore, a scar can be seen as a seam.
hope I made no mistake and that helps you.
Student or Learner