This is subjective to a few factors:
- Type of position being applied for.
- Years of work experience you have.
- Employer explicitly stating what they believe a reference is in relation to resume details.
In general, a reference should be an employment reference. I work in tech, have held full-time and freelance positions and have a fairly deep history. So my resume is focused on solid professional experience, but my reference list is a mix of full-time co-workers, managers and even freelance clients.
I mention years of work experience because you might have a natural/implied reference handicap that works for you if you are a recent graduate; high school, undergrad and graduate. In general, a sane/reasonable employer will see someone who is an high school or undergrad as someone who will naturally have limited professional references, so you might be able to pass on a “character reference” such as a pastor or a friend. But that said, a professional reference will always hold more weight. If unsure, you might want to say something like:
Here is a reference from my current employer, but as a recent graduate
the only other references I can provide are personal in nature. Please
let me know if you would like to be put in touch with them.
That said, in some fields references can be as simple as someone who casually knows you and your desires in life. For example, if you desire to work in the food/service industry, most staff is hired—or referred to positions—via word of mouth. So you could, theoretically, know someone who you play soccer with on weekends who could simply know someone who knows someone and even thought they have little professional connection, the natural “team” atmosphere of being on a soccer team would be understood as a positive for a back-of-house food prep gig.
That last ultra casual example is hyper specific, but since your post is not clear on your career/job specifics I thought I would add that.