Buying fabric can be an over welling experience, I hope this short description helps.
When buying fabric you'll need 2 sets of information: fiber content and construction.
Fabrics are made up of:
1 NATURAL FIBERS: Plant based or animal based such as cotton, hemp, flax, ramie, bamboo and jute.
Animal based fibers such as wool, alpaca, camel hair, silk worm, angora.
2. MAN MADE FIBERS: Polyester, nylon, acrylic, polyamid, lycra, spandex or elastane. All man made fibers
3. CELLULOSE BASED & MAN MADE FIBERS: Rayon, viscose, acetate and modal are cellulose base (from wood pulp) heavily processed to make the fiber.
These fibers are then categorised in staple fibers which are short strands such as cotton. then you have filament fibers which are one long continuous thin strand.
Staple & Filament fibers can be made from both natural and man made - silk worms are a good example of a filament fiber.
Fiber are blended to have the endless fabric blend combination e.g. wool/polyester - typically you have the filament fiber (polyester) and the staple fiber Wool) is twisted and wounded around the filament fibers.
Yarn is the result of the finish fibers ready to be either knitted or woven into fabric.
There are 2 types of fabric process - WOVEN OR KNITTED
WOVEN FABRIC: is a process that yarns go through a weaving of warp and weft - warp is the vertical yarn along the selvage and weft is the left to right yarn. Woven fabrics are normally non stretch, unless a elastane fiber is woven into it normally in the weft.
KNITTED FABRIC: Is a process of creating loops by inter-looping of yarns. usually creating a bit of stretch.
Hope this helps in your fabric journey.