The application and CV gonna tell who you are, what kind of education you have and what you have done. The application must state why you are the one who is right for the job, and tell your employer if you are the one they should aim for.
For an employer or recruiter, CV is a central source for information about you as a potential candidate for the position. These document are thus two of your most important branding tool in a job search process.
The reader of the application should understand that you fancy this particular job, have the right experience, that you have confidence and that you are fit for the position.