It seems that The Big One has discontinued the Glossary of sewing terms in their instructions pages, instead referring people to their videos explaining sewing techniques. While that may be useful on one or two levels, I don't need to watch a 15 minute tutorial on how to do a narrow hem or such. I can read about it and grok the method in less than a minute, and TBH, I know more than the so-called experts.
So for your sewing reference, here is a glossary of sewing terms and how-to's that you can read when you need them. I'll update as I think of other terms.
Double Stitch: stitch seam along the seamline, then stitch again 1/4 inch away inside the seam allowance, using a straight stitch or zigzag. Trim close to second stitching.
Alternative: stitch seam along the seamline, and use a serger/overlock machine 1/4 inch away inside the seam allowance.
Edgestitch: Stitch close to finished edge or seam on outside of garment.
Finish: Stich 1/4 inch from raw edge using a straight stitch, and pink, or overcast, or turn in along sticking and stitch close to fold, or overlock.
Optional for hems: Apply seam binding,
Narrow Hem: Turn in hem. Press, easing fullness if necessary. Open out hem. Turn in again so raw edge abuts the crease. Press. Turn in along crease; stitch; press.
Prickstitch: Bring needle through all thicknesses to the right side of the garment. Take a stitch back one thread (two, max), forming a tiny stitch. Bring the needle out a scant 1/4 inch in front of the previous stitch. Repeat.
Reinforce: Stitch along seamline where indicated in sewing instructions, using 1mm stitch length.
Slipstitch: Slide needle through a folded edge of fabric, then pick up a thread underneath the fabric.
Staystitch: Stitch 1/8 inch from seamline inside the seam allowance, using 2-2.5 mm stitch length.
Understitch: Open out facing or underside of garment. Stitch close (a scant 1/8 inch) parallel to seamline.