The Avalanche blockchain works through its novel architecture that allows for a universe of independent but interconnected blockchains, all validated and kept secure by dynamic subsets of validators. It is an open-source platform for building decentralized applications in one interoperable, decentralized, and highly scalable ecosystem. This is powered by a unique consensus mechanism that allows it to accommodate the scale of global finance with near-instant transaction finality.

The key features of the Avalanche network are: Speed, as it employs the fastest consensus mechanism of any layer 1 blockchain enabling quick finality and low latency; Scalability, as Avalanche is built to scale, allowing developers to build application-specific blockchains with complex rule sets or build on existing private or public Subnets in any language and is incredibly energy-efficient; Advanced Security, as the Avalanche consensus scales to thousands of concurrent validators without suffering performance degradation, making it one of the most secure protocols for internet scaling systems.

The consensus algorithm Avalanche uses is a family of protocols collectively called the 'Avalanche Consensus', with the core being the 'Snowball Algorithm'. This algorithm operates through repeated sub-sampled voting. When a node is determining whether a transaction should be accepted, it asks a small, random subset of validator nodes for their preference. Each queried validator replies with the transaction that it prefers, or thinks should be accepted. The node repeats this sampling process until the validators queried reply with the same answer for a sufficient number of consecutive rounds. In this way, if any honest validator accepts a transaction, all honest validators will eventually come to the same conclusion. These values, which are constants, are quite small on the Avalanche Network. The sample size, k, is 20. The quorum size, α, is 14. The decision threshold, β, is 20.