What is the difference between a DSLR and a film camera?

The concept of your question is a bit inappropriate,

"DSLR" was originally a concept from the film era, which has a history of 60 to 70 years, and now it is called digital SLR, which is, as the name suggests, a digital single-lens reflex camera.

The difference between the two lies in the change of the information recording carrier, a film, a photoelectric sensor CCD or CMOS plus memory card.

The lenses are the same, so the previous lenses are still in use today.

The level of automation in cameras has come on in leaps and bounds over the years, but it's not exclusive to digital SLRs; film SLRs of a decade ago were already quite automated, including autofocus, auto-exposure, and so on.

Good luck