Just like the meaning of the term “the right side of fabric” eluded me when I began sewing, I was also being unsure about backstitching on a sewing machine. And I’m guessing that if I didn’t know how to backstitch, there are probably a few other people that are trying to figure it out, too.
So, backstitching, as the name suggests, is really just sewing backwards. You backstitch to secure the seam you just sewed. If you don’t backstitch, then your seam will unravel.