I am trying to find out difference between 退職願 and 退職届 and 辞任 with example and explanation.
1 Answer
The clue to the difference between the first two is in the kanji used - a 退職願 is a formal "request" (願い) to leave one's position, so it has to be processed by the company and accepted before the employee is officially no longer employed. A 退職届, on the other hand, is a formal "notification" (届け) of one's resignation, so it is effective immediately and cannot be rejected or withdrawn.
辞任 is not equivalent to either of the above; rather it's parallel to 退職 on its own - it's a word for the act of resignation itself, not the document submitted. The difference between 辞任 and 退職 (and also the similar 辞職 and 退任) is subtle, and they can be interchangeable in many cases, but in essence the words using 任 refer to leaving a specific position whereas the words using 職 refer to leaving an entire company or profession. The words using 辞 place a certain emphasis on the fact that the employee is leaving of their own accord, whereas the words using 退 are more neutral and can also cover cases where the employee was requested/forced to leave by their employer.
Finally, though you didn't mention it, there's also the related word 辞表, which is a special form of 退職願 that's only used for certain executive positions.