What is a quilting fat quarter?

In quilting fat quarters are a popular way for patchworkers to purchase fabric.
This is mainly due to the dimensions of a fat quarter.
Fat quarters are pre-cut pieces of cotton fabric.
They are taken from one yard of fabric,cut in half lengthwise,and then in half width-wise.
The dimensions are approximately 18" x 22" (46cm x 56cm).
A normal quarter yard cut from a bolt would measure 44" x 9" (112cm x 23cm).
The squarer shape of the fat quarter rendered it more useful and open to a number of sew and piecing alternatives.
That's why patchworkers and appliquers love them so much.