Purge cache of a single page within a site?

[JBaker122586]

Man, I'm just all over this board bugging more knowledgeable people with my questions.

Anyway, I would like to know how I could go about purging the cache of a single page (or directory), so that when I update a single page on my site, users don't see the previous cached version when they navigate to that page.
Again, I know this is probably something really simple, but I'm in the dark.
Thanks in advance.

 

[angelwatt]

You can do it to an extent with meta tags. Check this page, which details the meta tags. You'll want to specifically look at Cache Control and Expires.

 

[JBaker122586]

Is that the only way to do it?
I feel like with cache control, the pages wouldn't ever really get cached and it would cost me bandwidth, and visitors loading time.
And with expires tags, I'm never really sure what exact date or time I'm going to update a page in advance until I do it.

Are there any other ways around it? Should there be something I can do through my server whenever I update?