Where is the back bump in crochet?

What is a slip stitch?

1 : a concealed stitch for sewing folded edges (such as hems) made by alternately running the needle inside the fold and picking up a thread or two from the body of the article. 2 : an unworked stitch especially : a knitting stitch that is shifted from one needle to another without knitting it.

IT\'S FUN:  What is the best bobbin thread?