This is the stitch made of the doubled Moss Stitch pattern. It is sometimes also called Checkerboard Stitch. Another elegant way to add texture to the knits.

Is often used in Aran knitting and for two-sided projects like scarves and blankets, as it looks the same on both sides.

FLAT KNITTING
Cast On: number of stitches, divisible by 4.
Row 1 (RS): (k2, p2) till the end of the row.
Row 2 (WS): as Row 1: (k2, p2) till the end of the row.
Row 3 (RS): (p2, k2) till the end of the row.
Row 4 (WS): as Row 3: (p2, k2) till the end of the row.
Repeat these four rows.

KNITTING IN THE ROUND
Cast On: number of stitches, divisible by 4.
Row 1: (k2, p2) till the end of the row.
Row 2: as Row 1: (k2, p2) till the end of the row.
Row 3: (p2, k2) till the end of the row.
Row 4: as Row 3: (p2, k2) till the end of the row.
Repeat these four rows.