Purl Stitch
Purl stitch is the same as the knit stitch really, the difference is that the needle to start with, is inserted from back to front through the stitch instead of front to back, and the yarn is wrapped from the front.
Yarn to the front
Yarn to the back
This has the effect of putting the knots on the back of the knitting as you go. (Whereas the knit stitch puts the knots to the front as you go.)
The purl stitch can be used for one row and then the knit stitch is used for another row, then purl a row, then knit a row continued. This has the effect of putting all the knots on the same side of the piece of knitting. This gives the resulting knitted piece a smooth, lighter appeal and is great for cardigans and jumpers.
The other use for purl is to knit one purl one. This is used a lot in patterns and it gives a ribbing effect – like on the cuffs of jumper and cardigan sleeves.
1) Insert the needle into the front of the stitch

2) Wrap the yarn around the front needle from back to front (Blue needle in the photos)

3) Slide the front needle down (blue one in the photo), roll the tip under the left (orange) needle and push towards the back, catching the stitch and taking the yarn with it.

4) Slide the new stitch off from the left (orange) needle. The yarn stays in front for the purl stitch.
