Are urls supposed to be accessible 2 ways?

[chy123]

When I look at some sites I see that their urls are accessible via

[domain...]
but also
[domain...]

Are you suppose to be able to access the urls both ways ?
My RewriteRules only allow access via
[domain...]

if you try the other url it goes to a 404 Page Not Found

[jdMorgan]

Is /folder a page in your root folder, or a directory index of a subdirectory called "folder"?
Are you rewriting these requests to a script -- or doing anything else to re-map the request?

To clarify your question, you see that some sites have the same *resource* accessible at two *URLs*. This is not good. But if the URL-path "folder" on your site is a "page" or a "file" located in your root directory, then you might also have a problem.

Jim