"Flat" or Vee Bed knitting machines consists of 2 flat needle beds arranged in an upside-down "V" formation. These needle beds can be up to 2.5 meters wide. A carriage, also known as a Cambox or Head, moves backwards and forwards across these needle beds, working the needles to selectively, knit, tuck or transfer stitches. A flat knitting machine is very flexible, allowing complex stitch designs, shaped knitting and precise width adjustment. It is, however relatively slow when compared to a circular machine.

A Circular knitting machine has a "Needle Bed" which is cylindrical, known as the CYLINDER. If you imagine the sides of a coffee cup with grooves machined in it equidistantly all the way around, you get the idea.

Some circular machines also have a second "Needle Bed", called the DIAL. If you now imagine a saucer with grooves radiating out from the centre, sitting on top of your coffee cup, you can get the image.

Both of these formats have advantages and disadvantages. Circular knitting is very fast, but has limitations in design scope when compared to a Flat machine.

The two largest manufacturers of industrial flat knitting machines are Stoll of Germany, and Shima Seiki of Japan.” Reference: http://en.wikipedia.org/wiki/Flat_knitting