CPC Concept Ka Chaos

Maine aaj class mein dekha, CPC me Dual Taxation Avoidance Agreements aur Avoidance of Double Taxation Agreements dono hi ho jaate hain. Ab main confuse ho gaya kya difference hai? Agar yeh dono hi kuch same karte hain to woh kya farq karta hai? Maine search ki thi, par ek clear answer nahin mil raha. Kuch log kehte hain ke yeh dual taxation se bachne ke liye hain, par kuch log kehte hain ke yeh foreign companies ko encourage karne ke liye hain. Yaar samajh nahi aaya, please help. Mujhe aisa lagta hai ki AILET exam mein isse puchhna hai. Koi sahi solution batao?