I hope this helps to explain the twist, it's a term that was used when spinning wheel did yarn and has been carried over in todays thread.
Also, if you get knots in your quilting thread, you can do one of 2 things. First, after you thread the needle, run the needle and thread through a Bounce drier sheet.
Second, this works better for embroidery thread, but can be used on quilt thread. Have a damp sponge, wrap it around the thread and drag it down the thread just before you are ready to use it.
The direction in which the yarn is spun is called twist. Yarns are characterized as S-twist or Z-twist according to the direction of spinning. Tightness of twist is measured in TPI (twists per inch or turns per inch).
Two or more spun yarns may be twisted together or plied to form a thicker yarn (this is todays serger thread). Generally, handspun single plies are spun with a Z-twist (left), and plying is done with an S-twist.