Kant's Categorical Imperative vs Social Contract Theory - kya difference h??

Yaar samajh nahi aaya, please help! Maine ye concepts padhe, lekin yeh lagta hai ki vohi ek hi cheez hai. Kant ke categorical imperative ke according, hum apne action ko universal maxims ke roop mein test karke unka rightness/dearness check karte hain. Jaise, agar hum apne parent ka khaana karne ke liye use khatra dega, toh yeh galat hai kyunki agar har koi apne parantu ko khatra dega, toh parent ko kuch nahin mil pata.

Lekin social contract theory ke according, hum society ke rules aur norms follow karte hain kyunki ve humein benefits pradaan karte hain.