You will have to choose the format in the cover letter if you write a cover letter for the request, you will have to apply the application. And if you are not writing for this request then you do not want to apply it.
Cover Letter Examples
Good Cover Letter Example
You should tell the whole of your experience in full detail in your resume, this is a good cover letter that describes you in a positive way.
Resume Cover Letter Examples
In this letter you have to prepare your own resume which has all your details and also your experience , this is called resume cover letter.