Bailment or Pledge? Aur mujhe lagta hai koi difference nahi hai!

Yaar samajh nahi aaya, I've been reading this for hours and I'm still confused. Can koi bhai mereko samajhne mein madad kare? I've got a paper on Property Law and I'm stuck on bailment and pledge. According to me, don't they both involve transferring possession of goods? But the professor said there's a difference. I've been researching, aur maine paaya hai ki pledge is a specific type of bailment, but kya? Kya pledge ke under bhi goods ki ownership change hoti hai? Aur kya isse bailment se alag hai? Please help! Any tips or examples will be super appreciated! Main to kuchh hi samay mein CUET PG Law ka paper dekhna hai!