what is this option about ?

[mecho]

Hi ,
i'm wondering to know about this option :

Cookies and HTTP Header Options > Add No-Cache HTTP Headers :

Selecting yes will cause vBulletin to add no-cache HTTP headers. These are very effective, so adding them may cause server load to increase due to an increase in page requests.

i read the explanation 10 times but i dont get it at all ( my English is not well 2 ) so i dunno it helps or what ?

is it possible that someone explain this option to me ?

thanks in advance

[Floris]

If you go to a different page, or return to the existing one, and there is an image there that's already in your cache, it will re-use that image. If you set it to no-cache headers, it will not re-use the image and force reload it from the server.

The latter means each time a page loads it will 100% be reloaded from the server, causing more traffic. 99% of the time you wish to turn off no-cache headers.