Jeanne is correct.
The advantage to using the page directive is that the import only get's done at compile time (think of it as pasting the two source files together before compiling). Since it's only done once, it's more efficient for lightweight imports.
One of the down sides is that everything always gets imported, even it it's not used.
Example:
In this case, both file_A and file_B will be included even though only one of them will ever be used.
The jsp:include will check the condition at run time and then import the correct file when needed.
Another thing to watch for with the page directive is that some containers (older versions of
Tomcat for instance) will only check the parent for updates. This means that if you update the code in your include file, the change will not show until you force a recompile of the page it's included in. Tomcat now checks both.
Also, one drawback to the jsp:include action is that the output from the included page can't be JSP that defines variables or behaviour used in the calling page because the calling page will have already been run before the include is.
[ January 01, 2005: Message edited by: Ben Souther ]