Patterns called cables are typically used on sweaters, particularly on fancy Aran sweaters from Ireland.
Different kinds of stitches create different patterns in knitting. For example, the stretchy ends of knitted sleeves are called ribbing.
Yarn for knitting can be made from any number of natural or synthetic (man made) fibers such as wool, cotton, silk, or acrylic. Some yarns are made from a blend of several kinds of fibers.
Yarns come in many thicknesses or weights from fine to thick: lace, fingering, sock, sport, double-knit (or DK), worsted, Aran, bulky, and super-bulky. Thinner yarns are generally used with smaller knitting needles, and thicker yarns are used with larger knitting needles.