This is Not a Big issue but actually, you can check here, @jamezmccoy has edited his initial comment after my comment and you know we did not get a notification for the edited comment hence I did not get a chance to re-visit his edited comment if he could simply reply on my comment and asked the same then I may reply him on time but still as I said this not a big issue.

Explain the Blockchain CryptoGraphy and mention few names which are the Blockchain Platforms?

mention a few names which are the Blockchain Platforms. This means you simply need to mention the names of the blockchain platforms.