How do DeFi farms work?

So, how exactly do these DeFi farms operate? Can you walk me through the process? Are they similar to traditional farming, but with digital assets instead of crops? Or is there more to it than that? I'm curious about how users can get involved and what kind of returns they can expect. And what risks are involved? Is it SAFE to invest in these farms? I'd appreciate it if you could provide some clarity on these points.