I am a developer. these days we are going to jump into Crypto well. So i have read lots of blog online how Crypto currencies works. But i am little confused for the private key.
1) Where it is stored in decentralised ledger.
2) How it is validated while sending payment to any other key.
Private keys aren't stored on the blockchain, just in the individual wallet of their owner. This is important because anyone with access to the private key can spend that user's bitcoins.
Transactions are validated by checking that their cryptographic signature corresponds to the public key of the sender. This is proof that the transaction was signed using the user's private key.
Have you read the Bitcoin whitepaper already?