Other differences are:
An article has one author and only he (and admin or groups with the correct permissions) can edit that article again. Wiki pages can be edited by all users by default, and a history of all the changes is kept, where you can roll back to, if someone did something stupid.
Besides that, articles only appear in a list, newest first, oldest at the end, you can access them only by clicking through the list or if you know the unique article id. Wikipages have a name you can use to quickly access them, like
Or if you use the example .htaccess file, you can even use