Warp and weft are two components to weave thread / yarn into a fabric.
Warp is the vertical thread. Weft is the horizontal one.
There are many different ways/combinations of warp and weft defining the characteristic of the fabric. Wether it becomes hard to bend like leather, or very easy like silk, etc.
Warp, Weft, and Shear and the three basic things defining how the fabric behave.
Warp stretch and weft strech control the stretchiness of a fabric. The lower the number, the more loose/relax/draping/hanging/longer a fabric becomes. The higher the number, the fabric pulls itself inward, thus it becomes shorter.
Shear controls the stretchiness of a fabric diagonaly.
Warp bend and weft bend controls how hard/easy the fabric bend. The higher the number, the stiffer it becomes, has less folds and creases, like leather.