The question has been asked, "What is the difference between fiber and yarn?" It's actually been asked more than once and I, in my wisdom, have neglected to actually give a meaningful answer. I forget that not everyone lives in my world, so here is my best effort at explaining fiber, at least in the terms that I'm familiar with.
Fiber is a raw material. It comes from plant sources (cotton, hemp, corn silk, flax, soy silk, bamboo, etc,) and from animal sources (wool, alpaca, mohair, silk, cashmere, angora, dog hair, llama, camel down, camel hair, etc.) All animals and all plants produce fiber in some form, but some are more usable than others and some fibers take some real creativity to find uses for them. I know absolutely nothing about plant fiber, so that's the last mention I'll make of that.
In my world, fiber is the bag of alpaca fleece you sink your hands into and breath in the earthy (and sometimes down right stinky) animal smell right after it comes off the animal, enjoying the total sensory experience--including the static electricity. It's still warm from the animal's body and the newly shorn ends look like a silk carpet.
It makes you groan slightly with the richness of color and luxurious softness. In my world, fiber is the mohair that smells and feels greasy until you wash and dry it so that it shines like silk and curls into perfect ringlets like doll hair. By the way, "fleece" is just another word for an animal's coat of hair that is harvested for use, usually some kind of wool. The blanket of an animal is the fiber that is shorn off of the sides, back, hips and shoulders. It the best fiber on the animal. The neck, leg, belly and...well... less desirable areas are normally either thrown away or used for things like garden mulch, lining chicken nests or animal bedding.
The first step in transforming raw fiber into something usable is skirting. This is where the entire fleece is spread out on a large mesh screen and sorted in order to remove impurities, unusable bits, and soiled fibers. During this phase, the wool is also sorted and graded according to fineness, color, and use. Some fiber will be coarse and straight (leg and belly hair) and most will be crimpy and soft (back, shoulder, neck, hip). Crimp is the wave in the fiber that gives it loft. Not all types of animal fleece will have crimp, but if crimp is a consideration, consistency in frequency and amplitude throughout the entire blanket area is important.
This first step is very important, as a poor job of skirting can ruin the fiber for it's intended use and create problems at every stage of processing. Imagine a gorgeous alpaca sweater in lilac and sage with tiny bits of hay stems scratching you every time you wear it!
After skirting, the fiber is washed and laid back out on the mesh screen to air dry. This is washed and dried alpaca ready for the either carding or combing. This animal has two colors in her blanket and the processed fiber should produce a tweedy marled looking yarn or felt.
If the fiber is agitated during the washing, it will mat itself into a shrunken, shaggy mess, beyond rescue and never to be used again. (How, exactly, would I know this? Experience, my dear, experience!) It will be a total loss, so the washing must be done by careful soaking with a mild soap and meticulous rinsing. I use my clothes washer only on the final spin cycle to spin out the rinse water. There's no matting and felting together as long as the whole mass moves in the same direction.
These fibers are mohair and they've been through a picker. You can see the huge sharp spikes in the picker and the resulting fluff. There are spikes on both top and bottom of this wicked thing and they pull the locks apart so they can be rearranged. Because mohair curls and twists, it benefits more than most fibers from being put through the picker unless you're using it for doll hair or spinning a curly novelty yarn. The young man running the picker is one of our Ranchers at Triangle Cross Ranch. He's decided that this is his niche and he loves running this machine--with heavy gloves and close supervision for safety.
After picking and fluffing, fiber is carded or combed in order to arrange the individual fibers so that they're all going basically the same direction. I like to dye raw fibers, right after washing because it adds interest to the carding and combing and it's ever so much fun to blend colors at this stage. Experimenting with different color combinations and imagining the finished products makes the work go quickly. (I've learned more about color theory on my drum carder than any class or instructor could have taught me.) Fiber off of a carding machine is called a batt or roving. If you're a quilter, you know what batting is and this is nearly the same, but made from natural animal fiber rather than polyfiber. You can use hand cards--two curved paddles with carding cloth (teeth) on each, but with the amount of fiber we produce a year, hand cards are kind of like trying to empty the ocean with a teaspoon. The white batts are mohair and the brown/gray is alpaca.
From a comb, the fiber is called top or sometimes a roving. This is a thin, continuous "river" of fiber that is ready for spinning. Again, the tools of the trade offer long sharp spikes and look like weapons of mass destruction.
So far, the fiber has progressed from fresh raw fleece, to washed and dried fiber, to combed top or carded batts and rovings. From here, it can be spun into yarn, made into wet felt, needle felted, locker hooked or anything you can dream up. Up to this point, it's been pretty much all work and no play. Dyeing the raw fleece helps, but it's still a lot of production work and not always pleasant. It can be dirty and smelly work, although quite satisfying for me. I just love to see a huge pile of carded batts sitting on the table after a good day's work. More than that, I love to see fewer and fewer bags of raw fleece sitting in my barn.
Enough for now. More later on two preparations that I consider the bridges between fiber and finished goods and the beginnings of the creative process--the magical, incredible, wonderful process of felt and the meditative, reflective, sometimes tedious process of spinning. Just think, we'll be knitting in no time! Whoopee!
One of our Ranchers has had some financial difficulties recently, falling behind on his account by a substantial amount. This young man has been living at the Ranch for 21 years, paying his own bills through government benefits and income from his part-time job as a busboy at a local restaurant. He's autistic, so moving him to another facility would be traumatic, tragic and disastrous for him. We're on a mission to find money for him so he can stay at the Ranch. It's been an exercise in creative accounting and problem solving. The good part is that all of the Ranchers will benefit from the final outcome. It just stinks that everything seems to be about the money... Our young man has no idea that there's a problem and, hopefully, will never have to know. 
The Ranchers continue to make hand made felt throughout the winter. They should be finished with all of the fiber in the workshop by the end of March so they can spend more time on the gardens. We'll shear again in May.
We took all of our 2 year old and older angora goats to the sale in January to save on feed costs. The newborn spring angora kids will arrive in June, but we'll be bottle feeding about 25 dairy goat kids in a couple of weeks for a local goat dairy. We'll rotate babies in and out as they grow out of the bottle feeding stage right through to the end of spring. 
