Wool hats are made of soft animal fibers. Most often merino sheep or lamb, but can be alpaca, camel, llama, or angora goat. Because of the insulating air pockets, wool hats are warm. Wool yarn is used to knit and crochet hats and mittens, or woven into textiles.
Boiled Wool Hats are made by shrinking knitted or woven wool or wool blend fabrics in hot water. This creates a tighter felt-like fabric. Berets, beanies, and hats are made of boiled wool. These hats have a stretchy, comfortable fit. Boiled wool hats are washable as they are preshrunk. They are packable.
Wool Felt Hats are made from wool fibers matted together in steam and alkali. It is not woven, so it won't unravel. Natural wool has a waxy coat on its surface that makes wool hats naturally water- and stain-resistant.
Wool blend felts, usually wool felt and rayon blend. Softer than 100% wool felt, wrinkles more easily, only slightly water resistant. How much of the benefits of wool is retained depends on the percentage of wool vs rayon in the blend.
Bouclé yarn is made of two plies of uneven tension, creating loops and curls. Bouclé fabric can be knitted or woven of bouclé yarn. It appears nubby. It can be wool, wool blend, acrylic, etc.
Tweed is a closely woven, rough-surfaced wool fabric. Woven from multicolor wool yarn by plain or a variation of twill weave (herringbones, diamonds, chevrons, check weave. Tweed is also made of wool blends.
Cassimere is a closely woven wool fabric.
Cashmere wool is obtained from cashmere and other types of goats. Cashmere wool is softer, finer, stronger, and more insulating than other wool. But not all cashmere is alike. There is an enormous price difference due to the length and strength of fibers.