[kevs]

Could someone please explain main differences between the function of cache and cookies. I have Safari enhancer set to de-activate my cache, but still it seems that certain web pages load slow, but then very fast on second try, why?. Also, I create new web pages, and upload them and have to refresh to see new version even though cache is deactivated ( and Safari cache folder is indeed empty)

[Turias]

Cache: Stored images and raw HTML.
Cookies: Stored information (usually login-related) so that a webpage can "remember" you and alter it's functionality depending on what you have done.

I'm not sure about your uploading issue, but I have noticed that something even as low-level as SSH can take a really long time to connect the first time, but if I disconnect and reconnect, I connect almost immediately. It might be that your computer no longer has to do a DNS lookup.

[kevs]

thanks Turias.

What do you mean by alter it's functionality?

What does doing a DNS lookup mean?

Today when I went to one of my webpages it took a long time. Then I immediately clicked out of it, then went back to the page, and it came right up. What facilitated it coming up fast second time?

Any idea why I have to refresh to see changed pages even though cache is de-activated?

[ginoledesma]

DNS lookup means that your computer has to figure out what an address like "www.apple.com" is. Computers see things in numbers (binary, actually, but let's just say numbers for now), so something like "www.apple.com" has no real meaning to it. It has to do ask a Domain Name System (DNS) server to translate it to something it can understand. In this case, the DNS lookup returns "17.254.0.91" for "www.apple.com" (you can try this out using the Network Utility application in Applications > Utilities).

DNS lookups are "cached" (stored in memory for fast retrieval). That way, your Mac doesn't have to ask the DNS server to translate "www.apple.com" again, because it remembers it. This is one way to improve performance (which is what makes caches very important).

As to your browser cache, it works the same way: the browser "saves" the sites you visit in its cache (disk and/or memory), so that if you visit the same page again, the browser doesn't have to request it from the web server. Of course, its not as simple as this, but you get the picture.

Knowing that, you'll then know that "outdated" caches tend to be a problem, as you've experienced. Safari might still be caching the page in memory (which may not be deactivated), so a refresh forces an update of the page. One other possibility is that your Internet Service Provider may be transparently caching for you (that is, they have their own cache), which is common in some areas that have broadband/dialup services.

[kevs]

Thanks gino, great reply.
I de-activated my cache in Safari with safari enhancer, becasue I found without it de activated, it would spin on and on looking for site sometimes. Having it off, grayed out is way better.

but you explanations explains, perhaps why, I still have to refresh, something they could not even explain.