CrPC Section 173 aur Section 154 ke beech kya antar hai?

Mujhe lagta hai ki dono sections ka dhanda samajhne mein mera bharosa khata hai. Section 163 mein police ko FIR register karna padta hai jab woh kisi galtiyon ka shikar hojaate hai. Lekin Section 173 mein FIR file karna padta hai lekin iske alawa police ko ek specific report bhi submit karna padta hai. Mujhe pata nahi ki dono sections mein hain toh phir bhi ismein kya fark hai? Kya unki use court mein dala dala ja sakta hai? Someone batao, main to abhi section ke rules samajhne ke liye kagaz par bhidbhid kar raha hoon.