What is a "needle plate"?

A needle plate, also known as a throat plate, is a small metal plate located on the bed of a sewing machine that has a small hole for the needle to go through and is designed to keep the fabric flat and in place while it is being sewn. The needle plate has various guidelines and measurements to help the user to sew straight seams and keep the fabric aligned correctly. Additionally, some needle plates have a small slot to allow the user to insert the bobbin case, which holds the bobbin thread that interlocks with the needle thread to form a stitch. Needle plates are an essential component of any sewing machine and are removable for cleaning and maintenance.