What is the Blockchain?

The blockchain is a registry that contains the history of all exchanges made between its users since its creation. This registry is secure and distributed: it is shared by its various users, without intermediaries, which allows everyone to check the validity of the chain.

In other words, it is an accounting ledger that is immutable. Once a transaction is entered into the blockchain, it cannot be altered.
Once a transaction has been entered into the blockchain, it cannot be altered.

Specificities of blockchain are : transparency, traceability and integrity.

When you buy Poken, the transaction corresponding to the purchase of PKN is written to the blockchain.