Fresh Pages

How does google define fresh?

[davejs]

Hi

How does google know if a page is "Fresh" or has recently been updated? Is it just using its cache to check for differences? or can it see a date that the page was last re-uploaded?

Thanks

[davejs]

No answers yet... anyone?

[j4mes]

There are Last-Modified and If-Modified-Since headers that are sent with most pages when they are requested.

There's a bit on it from the w3 here: [w3.org...] read the "14.29 Last-Modified" and "14.25 If-Modified-Since" sections.

I *think* that's how they do it, though I could be way off... :)