A cover letter is a letter of introduction to an employer, which is used to formally submit a resume for employer review. The purposely of the cover letter is to identify your intent to "apply for" or "seek out" a specific position within a company. it also formally presents yourself as available for a job position or range of positions within a company.
Most importantly, the cover letter is an opportunity to quickly introduce yourself and grab the employers attention. Like the resume, it is another chance to market yourself to the hiring manager, promoting them to read your resume and ultimately grant a job interview.
A cover letter is a critical part of the job search process. It allows you the first opportunity to gain some interest from the employer. In our research, we have yet to find one career or resume writing professional that doesn't recommend sending a cover letter with every resume that you submit.