Circular knitting is when you create something that has a circular pattern without leaving a seam behind. Some of the most common articles of clothes that use this type of knitting are socks and mittens. When you use one of these machines, you will find that the knitting principles of this circular design are very similar to that of a flatbed machine. The main different is that you can keep going with a circular machine because there is not good to be a start and a stop point because you are knitting without seams.