Crocheters have used various other names to describe this stitch. Many people refer to it as "rib" or "ribbing." According to The Dictionary of Needlework, this stitch is also known as "ribbed stitch" and "Russian stitch."
Knitted ribbing is familiar because it's often used at the sleeves, necklines and edges of sweaters, but ribbing need not always be knit. Crochet work can mimic the look and feel of knitted ribbing as well.
There are many different possible ways to make ribbed crochet. Back loop single crochet, as shown here, is one of the simplest ways to make crocheted ribbing.
How to Work Back Loop Single Crochet:
View A - Solid Back Loop Single Crochet: This swatch was worked in Cascade 200 wool yarn in Robin's Egg Blue.
To work a sample like this one, start with a foundation chain of any number of stitches. Single crochet in the second chain from your hook, and in every chain afterwards across the row. At the end of the row, work a turning chain and turn.
For the second row of single crochet stitches, work only in the back loops. Work one single crochet in each single crochet stitch across the row.
Repeat the second row as many times as you need to, always working in the back loops only.
View B: This photo shows the same swatch, flipped on its side. When you flip it like this, it looks and performs a bit more like ribbed knitting, with the stretch going in the same direction that you'd expect from a knitted rib.
View C - Striped Back Loop Single Crochet: See instructions.
View D: This photo shows how the striped fabric looks when it is flipped on its side. In the team spirit hat pattern, the crochet work is flipped like this to make the best use of the fabric's stretchiness.
There are so many more possibilities for using back loop single crochet. You can play with creating many different stripes, color combinations, and colorwork patterns.