What is the relationship between fibers yarns and fabric?

A fibre can be a thin thread from either natural or synthetic sources, such as a seed hair from a cotton boll. Fibres are usually spun together to make continuous strands, which may be further combined by twisting. This is called a yarn. Yarns can be knitted, crocheted or woven into flat sheets which are called fabrics.

However the terms are often used more loosely.