What is a "feed dog"?

A feed dog is a component of a sewing machine that helps move the fabric through the machine as it is being sewn. It is a metal or plastic plate with teeth that stick up and grip the fabric to move it forward. The feed dog works in conjunction with the presser foot to hold the fabric in place and move it under the needle. The speed and size of the feed dog's teeth can be adjusted on some machines to accommodate different types of fabric and sewing techniques. Without the feed dog, it would be difficult to sew evenly without pulling or bunching the fabric.