This is probably, the first stitch you need to know before learning any other embroidery stitches. It is a simple single stitch done by taking the needle in and then out of the fabric. Most stitches begin by making a single straight stitch. Apart from that, many straight stitches can be combined in various ways to come up with various patterns.
A series of detached straight stitches form the running stitch. So, I have mentioned and shown the running stitch family as a member of the straight stitch family.