Scale, Finalization, and Consensus

Popular blockchains like Bitcoin and Ethereum enable decentralized nodes to add transactions to blocks. These transactions must then gain consensus from all nodes before the block is accepted onto the chain. The approach involves agreeing on one block at a time.

This method results in a compromise. Even if a block is theoretically approved by most nodes, if a transaction within it is later deemed false, the entire block may be reversed—removed from the chain. Valid transactions then need to be included in a new block.

The consensus mechanism also impacts scalability. When every node must validate and store each block, the saying "your chain is only as strong as your weakest link" becomes relevant. This means the system's performance is constrained by the transaction speed of the slowest nodes.