Flow is a blockchain that has been developed by the team that created CryptoKitties in 2017. Flow was created to provide solutions and applications for scalability for things like apps, games, and other digital assets. The goal of Flow is to provide a blockchain that avoids sharding on the network and maintains reliable decentralization.
Rather than having every node store all the data of the blockchain, Flow separates jobs and data between five different node types. The purpose for splitting the work between nodes is to reduce time and effort put into the nodes in order to improve efficiency. This addresses the Verifier's dilemma through a technique that Flow creators developed known as 'SPoCKs', or Specialized Proofs of Confidential Knowledge.
The team also created Flow with the intent to bring developers and consumers the ability to use upgradeable smart contracts and other features like human-readable security. The blockchain uses a Proof-of-Stake algorithm, developed by VMware Research, and smart contracts are ensured that each transaction has ACID (Atomicity, Consistency, Isolation, Durability) guarantees.