What is blockchain and how can it help small scale farmers and coffee producers get a fairer deal?

I keep hearing about blockchain technology and how it could benefit farmers, especially in countries like Ethiopia where coffee is a major export. I would like to understand what blockchain actually is in simple terms, without technical jargon. How does it work and why do people say it can help small scale farmers and coffee producers? Can blockchain help farmers get paid more fairly, trace where their produce goes, cut out middlemen, or prove the origin of their crop to international buyers? Are there real examples where blockchain has already helped farmers in Africa or other places? What would a small coffee farmer in Ethiopia need to do or know to benefit from this technology?