Confusing Concept: Consideration vs. Promissory Estoppel

Yaar, please help. Maine ye question 3 baar padha aur abhi bhi samajh nahi aaya. I read about consideration in contract law, sab keh raha hai yeh baniya ki duniya hai, wala hai naya deal ka. Lekin phir bhi Promissory Estoppel ka topic aata hai, woh bhi consideration se juda hai. Kya ye dono hi same hi cheez hain, ya phir different? Main confusion mein hoon. Kya Promissory Estoppel bhi wala hai naya deal ka? Lekin koi specific performance hai, koi enforcement. Main khudko samajh nahi paa raha. Please, someone clarify.