These two YouTube videos provide tutorials on how to tie different types of knots. The first video demonstrates how to tie a reef knot, which is useful for tying two ropes together of similar thickness. The second video shows how to tie a bowline knot, which forms a fixed loop at the end of a rope that will not slip or draw tight under load. Both videos provide clear, step-by-step instructions and illustrations on tying these basic but useful knots.