Patent ya Design ya Kya Hai?

Bhai, main socha tha ki woh kuch alag hai, lekin ab main confuse hua hoon. Patent, design, trademark sab kuch aapke haath mein aa jaata hai, aur sabse bada difference kya hai. Main ek assignment mein question aaya hai jiska answer nahi pata. Agar aapne koi product banaaya hai, fir aapko uske design, shape, appearance, ya fir kisi cheez ko kaise protect kar sakte hain? Abhi tak main socha hoon ki design ka concept aur shape dono hi patent ho sakte hain, lekin isme complications aati hai, kyunki yadi aapne product ka design badla hai, to kya woh design ab bhi patented hai ya nahi? Ya design ka protection karte samay kya rules hain?