Note: This information is taken from Wikipedia, the online dictionary. See http://en.wikipedia.org/wiki/Knitting
Knitting is one of several ways to turn thread or yarn into cloth. Unlike woven fabric, knitted fabric consists entirely of parallel courses of yarn. In practice, knitting is usually begun (or "cast on") by forming a base series of twisted loops of yarn on a knitting needle. A second knitting needle is then used to reach through each loop (or stitch) in succession in order to snag a bight of yarn and pull a length back through the loop. This forms a new stitch at the top of the current wale of stitches (or loops).
The two basic stitches are knit (or "plain") and purl (or "wrong"). These two nominal stitches are actually identical, however, being the obverse and reverse of the same stitch. If only knits or only purls are used when working back and forth in rows, the result is called garter stitch.
Alternating rows of knits and purls result in stockinette or jersey stitch, the stitch most often used in commercial garments such as T-shirts. Different combinations of stitches can be used to form ribbing, cables, or other textures. Complex patterns can be formed by knitting with multiple colours.