Why the name 9 patch given to nine patch png images

Question

I know how to work with 9 patch. But not aware of why the name is 9 patch. I can understand its 9 tiled. But what does that mean?

Google doesn't give enough and any information about this. Anyone who knows, please explain it here. It is really helpful

Answer 1

To make scalable square with rounded corners need to cut square into several pieces: 1)left-top corner 2)right-top corner 3)left-bottom corner 4)right-bottom corner 5)top line 6)bottom line 7)left line 8)right line 9)middle part

Parts from 5 to 9 scaled.

Answer 2

Google always has enough information. You just need to know what to query. In this case, I queried for 9 Patch:

The 9-Patch gets its name from the fact that the overlay created breaks the image up into nine defined regions, organized similar to tic-tac-toe.

And a nice little graphic example:

http://wiresareobsolete.com/wordpress/2010/06/9-patches/