IPC vs BNS - Main Difference Kaam Kyo Nahi Kar Raha

Maine socha tha IPC aur BNS dono hi hain same hi, lekin abhi tak classes mein gaya hoon to ye pata lagya hai ki dono alag-alag hain. Toh kya hoga kya, maine socha hai kabi bhi koi IPC se BNS ke kanoon ka reference na karega, jaise ki abhi tak aaya hoon to BNS mein IPC ka reference aaya hai, lekin IPC mein BNS ka reference kahan hai? Maine ye sawal professor ko pucha karonc toh kaha hai ki yeh kuchh aisa hai jise main samjh sakta hoon, lekin ye samajhne ke liye mera brain kaam karn band kar diya hai.