Cable back is a shorthand term used in knitting instructions that tells you to make a right-slanting cable. The instruction is usually seen as an abbreviation, such as C6B, which means cable six back.
To form a cable six back, you would slip three stitches purlwise onto your cable needle, then hold the cable needle to the back of your work while you knit the next three stitches off the left-hand needle.
To finish the cable, knit the three stitches from the cable needle onto the right-hand needle. This will produce a right-slanting cable.
You can also make left-slanting cables through a technique called cable front.

