Contract v/s Agreement: Fark Kya Hai?

Maine socha tha I understand Contract, and then the paper happened 💀. Ab koi mujhe bataye, difference kya hai? Kyu ki dono mein kuch aisa ho raha hai jo mujhe confusion mein daalta hai. Kuch log kehti hain ki Har agreement contract hai, lekin kuch log kehti hain ki Har contract agreement nahin hota hai. Aur phir koi kahega ki yeh to both hi ek hi cheez hai. To koi bataaye, what's the exact difference?

(PLZ respond with a proper explanation or any reference to a useful chapter/section.)