OK GG - here goes!

Imagine when you normally buy fabric you just measure the amount that you want off the roll and that is how much you get.

When we talk fat quarters we are talking 1/4 of a yard. A ? of a yard is about 23cm. So the piece of fabric that you would get if it was just cut straight from the roll is 23cm by normally 90cm (long and thin).

In comparison a fat quarter is a half yard piece cut in half the other way. So it is about 46cm by 45cm. So it is far more useful when it comes to quilting and craft projects.

Does that make sense?