If you ever played with hand stitching as a child, this is probably the stitch you did. I was four years old the first time I remember holding a needle and thread. The neighbor girls showed me how to sew the edges of fabric together for a Barbie purse. I’m pretty sure I cut the thread after doing the stitching without knotting off. I do know these first attempts were a running stitch.
Even before that I had lacing cards similar to this:
I remember playing with them in church. Going around the shapes was the running stitch. (If you click on the picture, it should take you to the eBay auction for these.) I haven’t seen any lacing cards for years. After searching the net for a picture, I know they are still available.
All that to lead into a video of the running stitch.
The first time I did a running stitch was when I was 20, and made my first quilt. By hand. And cardboard templates, lol. Took me 20 years.