Thank you for your reply. Now I am understood our paper wallet bitcoin is storing in Blockchain.
Transactions are stored on the blockchain not your paper wallet. Paper wallet is your private keys written on a paper. It is a bit similar to your email password and writing it on a piece of paper.
So database is Blockchain.
Yes.
We are getting only access for entering in bitcoin with Public key and and protecting with private key. Right?
Your public key is what you can give to others, which you see, store and give it to others as base58encrypted string (starts with 1 or 3).
And your private key is your secret information that you should never give anyone, and keep it safe. You usually see it as a base58encrypted string (starts with 5, L or K)