This may be a bit of an obvious question, but I still thought it was worth asking. I am building a fairly complicated site with a lot of includes.

In terms of content that needs to be on every page, is it actually faster to use include files (I know it is better for maintenance). I am wondering if anyone knows (for sure) if browsers cache include files. So for example page looks like this:

PAGE 1:
<include "includes/phpFunctionsNeededOnAllPages.php">
<include "header.htm">
<include "includes/menu.htm">
<p>individual body content for page 1</p>
<include "includes/footer.htm">


PAGE 2:
<include "includes/phpFunctionsNeededOnAllPages.php">
<include "header.htm">
<include "includes/menu.htm">
<p>individual body content for page 2</p>
<include "includes/footer.htm">

Does the browser cache the data in all of the include files? So when the next page is loaded, it doesn't have to check or reload the phpFunctions/header/menu/footer and just loads that pages body content? Does it cache the include files these the same way it would cache any other set of html pages?