Asking about cache system??

[sleepykim]

I am newbie in vBulletin and server setup.

I am trying to find the way to reduce database queries to help my site running smoothly.

In VB admin control panel, I found the feature called cache system. As my understanding, cache system is the system to record pages generated from php script into memory. If the pages are not change, next viewer can load the pages directly from memory without bothering PHP and database engine.

Above is my understanding, but when I observe mysql query log. I found that the system still query MySql in every loaded page. So, it means the cache system doesn't help, or my understanding about cache system is wrong.

Could someone help me please??