Clear background, Yes or no?

I've tried several ways to test what happened when setting"Clear background" yes or no;

however, I can't see any difference on PC browser.......

Can anyone explain what happened when setting Yes/No?

I know setting "no' will benefit the performance of mobile devices,

but know nothing about what it exactily do.

Thanks.

I think it means that the layout's background colour will not be rendered?

Meaning that if you have nothing covering it, you will see through the canvas?

Oops, the 'clear background' property was not in the manual. I've added it. Does that help?

Thanks, it really helps.