The most common type of these are tapestry needles, which are used for needlepoint and counted cross stitch. With a blunt needle it is almost impossible to pierce the threads of your ground fabric. Sharp needles come in a dizzying array of sizes and shapes. Sharps are basic sewing needles. Betweens are shorter than sharps and made to take tiny quilting stitches.
Beading needles are very long, very thin, and very sharp.
These are used for all kinds of beadwork. There are special needles for sewing upholstery, leather, hats, and just about anything you can imagine. Virtually all of these have sharp points. If you are having trouble threading your needle, turn the needle over. One side is slightly larger than the other.