A purl stitch is a fundamental technique in knitting that creates a textured pattern on the fabric. It is formed by inserting the needle into the front of the stitch and wrapping the yarn around the needle before pulling it through. This results in a stitch that appears bumpy on the front side of the work, contrasting with the smooth appearance of a knit stitch. Purl stitches are often used in combination with knit stitches to create various patterns, such as ribbing or seed stitch. Understanding how to perform a purl stitch is essential for knitters, as it opens up a wide range of design possibilities in their projects, including items like scarves and sweaters.