What is understood under the term "application"? (Europe, Switzerland)
It is a vague term and all of the required documents will differ between universities and countries. If you are applying directly to a professor (as opposed to an online form) then he/she should let you know if you are missing anything from your application after you apply.

Also, if the department or professor has a secretary then it might be a good idea to contact them as well to ensure you get all the documents to the right place.