Cabinet pulls and knobs, also known as decorative hardware, come in tens of thousands of shapes, styles, sizes and colors.  Many kitchens use both knobs and pulls—one type for the doors and another for the drawers.  Just be sure to choose knobs and pulls from the same collection or with complementary stylings to maintain continuity. 

Knobs tend to be circular in shape, often with faceted edges.  If you decide to change your cabinet hardware, a knob's one-point suspension is easier to replace than a pull. Pulls vary in length, so you have to consider distance between the two holes. Also, with a pull, oils and digging fingernails are more likely to affect the cabinet finish.