What does single reverse and double-sided mean?

What does single reverse and double-sided mean?

A single reverse flag is made by printing your image on the front of the flag with full penetration of the ink that allows the design to be seen in reverse on the other side of the flag. Most flags, including state and international flags are made single reverse.

A double-sided flag is made by sewing two flags together with a liner in between.As a result,no images or text is displayed in reverse.