The purl stitch is sometimes thought of as the opposite of a knit stitch. The purl stitch is yin, the dark, shady hillside, the the knit stitch's yang, the bright, flat open space.
It might seem like a strange metaphor, but it's actually pretty accurate. Even the look of the knit and purl stitches bears this out: the purl stitch is a raised loop, while the knit stitch is a flat half-V.
When you look at something made in garter stitch you see the bumps and flat spaces clearly, even though you performed the same knit stitch over and over. That's because the "front" and "back" of a knit stitch look different -- the back of a knit stitch looks the same as a purl stitch.
They really are two parts of the same whole, just like yin and yang. But how do you make a purl stitch? The steps are the same as when making a knit stitch, but the form is slightly different.
