A 51% attack occurs when a person, or a group of people, can stop Bitcoin transactions and even cancel them by having the majority of the mining power to do so.
Mining is an essential part of Bitcoin’s protocol, where specialized computers called ASICS add the final round of transactions to the blockchain.
Therefore, mining operations mustn’t become too centralized, which is why China’s Bitcoin mining ban in 2021 was welcomed, as all mining power was distributed across the world with ASICs looking for a new home.
Due to the size of Bitcoin’s network, a 51% attack becomes much less likely, but the same cannot be said for shitcoins…