There are two basic kinds of fabric: knits and wovens. They can be made from the same types of fibers, but they are made differently and so have very different material properties.
Knits are made of one continuous thread. Woven fabrics are made of two sets of individual strands.
Machines create knit materials using hand-knitting techniques. The material is a sheet of “stocking stitch.” The machines used to create woven materials are called looms, which interweave fibers both horizontally and vertically.
Knit fabrics stretch because of the loops in the fibers. Woven fabrics do not stretch because their fibers run at 45-degree angles to one another.
Woven fabrics have a visible bias, or nap, that must be cut so the bias on each piece matches when sewn. Knits do not generally have a nap.
Knit materials include jersey, berber, mesh, toweling, felt and fleece. Woven materials include linen, denim, twill, satin, chiffon, corduroy, tweed and canvas.