How Is Data Added to a Blockchain?

How To Store Data On Bitcoin Blockchain

Although anyone can add data to a blockchain, they cannot do it unchecked.

Let’s take a step back. There are multiple copies of a blockchain (Blockchain explained in 10, 100, 1000 words).  Every node (i.e., computer) on a blockchain network keeps its own local copy.

When a transaction occurs, several nodes need to verify it. They check that the sender has sufficient funds and that they are the genuine account holder, among other things. Once verification is complete, the transaction is approved, and every node updates its copy of the blockchain ledger. (Blockchain Definition with Example)