Burying the Knot
In machine quilting many quilters prefer to have no “start and stop” stitches (locking stitches taken in the same place). Instead they prefer to leave the tails of the threads hanging (always with BOTH threads on the TOP of the quilt
(watch this video if you do not know the importance of bringing up the bobbin thread) and they “bury the knots” after the machine quilting is done. Here is quilt teacher Jo Ann Gruber of Eagle River, Alaska demonstrating how to bury the knot in two videos:

