Scalability
A network's capacity to handle more transactions and users without fees and delays spiking.
Scalability measures whether a blockchain can grow without choking. Bitcoin handles roughly seven transactions per second; Ethereum's base layer, around fifteen to twenty. When demand spikes, fees climb and confirmations lag, as users learned during the 2021 NFT boom when a simple swap could cost over fifty dollars.
Most scaling work now happens off the base layer. Rollups batch transactions and post compressed proofs back to Ethereum, pushing effective throughput much higher. Other chains chase speed at the protocol level. Every approach trades something away, which is the heart of the scalability trilemma.
Related terms
Vitalik Buterin's framing that blockchains trade off decentralization, security, and raw scale against each other.
Layer 2A separate network built on top of a base chain to process transactions faster and far more cheaply.
Transactions Per Second (TPS)A measure of how many transactions a blockchain can confirm each second under load.