1. Tell me the reasons I should hire you that I won't find in your resume. Those side projects you did that you found really challenging. What subjects you found really interesting in school that apply to the position. Why you find the businesses subject fascinating. This is your chance to tell me on your own terms why you're a good fit.
2. Why are you applying for this job. What makes you fit this position. I'm not always looking here for direct domain experience, but something in your background or interests which fit with the role I'm hiring for.
I had a cover letter template that I would use but would always tailor cover letters to the specific job and organization I'm applying for. Only maybe 40% of the content of the letter came from my template.