The basic stitch used in cross stitch looks like an X on the fabric. There are other stitches that are associated with cross stitch such as Long Arm Stitch (Looks like an elongated X on the bottom), Double Cross (A cross with a plus), Herringbone, and many more. You would use decorative stitches such as backstitch, French knots, lazy daisy, and satin stitches to finish the design.
The most common stitches in Needlepoint are in the Tent stitch category; these are the Basketweave, and the Continental stitches. There are also regional stitches. As with cross stitch decorative stitches are added to enhance the final design.
Crewel, in contrast to cross stitch and needlepoint, is worked on the surface of the fabric and the stitches are not laid out in a grid. There are a lot of stitches used in one design; the most common are Stem, Chain, Satin, and Couched stitches. The variety of stitches makes Crewel challenging and a good way to learn new stitches.
The three main embroidery stitches are Cross Stitch, Needlepoint, and Crewel. This web site will explain the difference between each type, give examples of the stitches and finished designs done in each type. Also there will be other type of stitches mentioned.
Embroidery is the art or handicraft of decorating fabric or other materials with needle and thread or yarn. Embroidery may also incorporate other materials such as metal strips, pearls, beads, quills, and sequins. A characteristic of embroidery is that the basic techniques or stitches of the earliest work-chain stitch, buttonhole or blanket stitch, running stitch, satin stitch, cross stitch-remain the fundamental techniques of hand embroidery today.
Taken from Wikipedia