There are basically two types of cover letters that you may need to use depending on your current situation. An application cover letter is a type of cover letter that is used when the available role is already known and you intend to make it as your opening statement before the resume is read. Another type is the prospecting cover letter that is basically used if your intention is to inquire about open positions. While it is true that these types of cover letters might differ in content, they essentially follow a fundamental cover letter format. The best format is usually made up of three main portions _ the introduction, the main body, and your closing statement.
To ever have a chance of succeeding with your goal of landing that perfect job, you also need to dedicate some time and effort in crafting a good resume cover letter while ensuring that it maintains the structure of a proven and successful format. The cover letter essentially sums up your competencies and skills relevant to the role you are applying for. It is not generally considered as part of your resume, but you have to keep in mind that a cover letter becomes more effective if it complements your submitted resume.