13.1.6 Links between published files

To create a link from one Org file to another, you would use something like ‘[[file:foo.org][The foo]]’ or simply ‘file:foo.org.’ (see Hyperlinks). When published, this link becomes a link to foo.html. You can thus interlink the pages of your "org web" project and the links will work as expected when you publish them to HTML. If you also publish the Org source file and want to link to it, use an http: link instead of a file: link, because file: links are converted to link to the corresponding html file.

You may also link to related files, such as images. Provided you are careful with relative file names, and provided you have also configured Org to upload the related files, these links will work too. See Complex example, for an example of this usage.