Section 300 IPC se abhi tak samajh me nahin aya kya problem

Ye kya hai, maine ye section 3 baar padha aur abhi bhi kya samjhne ka prayaas kar raha hoon. Agar kisi ko apni life protect karne ke liye koi zehar khana pada to woh murder karna hai ya manslauger karna? Kya isme difference hai? Maine suna tha ki Section 300 me aapko intention ka concept aata hai, lekin maine phir bhi ye nahin samajhne ka prayaas kiya hai. Agar koi apni life protect karne ke liye koi zehar khata hai, to woh zehar khane ki intention se hi murder kar raha hai, ya phir woh karta hai manslaugher?