Wrap & turn short rows are usually the first method a knitter learns for the shaping technique. It’s an easy way to pull the rows together without leaving a hole.
To work a wrap & turn (often abbreviated “w&t”), simply knit (or purl) to the specified stitch, slip the stitch to your working needle bring the yarn forward if you’re knitting/back if you’re purling, and slip the same stitch back to the left needle. Turn the work and continue in pattern.
What you’ve done is create a wrap around the slipped stitch; it’s almost like a little scarf. And that scarf will help anchor the stitch to the row above – minus a hole!
When your work brings you back to the stitch with the wrap, the instructions will tell you how to handle it. More often than knot, the instructions will say to pick up the wrap and knit it (or purl it) with the stitch. So, pay attention to the lie so you don’t twist the wrap or the stitch, and knit them together. Here’s a video:
Wrap & Turn Short Rows: