Liability in Nuisance vs. Rylands v. Fletcher: Kya Fark Hai?

Yaar samajh nahi aaya, please help? Main confusion mein hoon ki nuisance aur Rylands v. Fletcher ke beech koi farq kya hai? Both mein bhi kisi aise vishay ka upyog ho raha hai jo kisi aur ko nuksaan pahuncha sakta hai, likin main samajh nahin paya ki hum dono mein kya sahi hoga?

Nuisance mein bhi property ka upyog is tarah karega jo dusre ko nuksaan pahuncha sakega, jaise ki koi factory jo pollution karte hain. Lekin Rylands v. Fletcher case mein bhi kya hai?