Blockchain technology is still at an early stage. It will take many years before it becomes mature and its potential is fully explored and harnessed. Currently, there is no universally agreed way to classify or define blockchain generation.
In her book on blockchain, Melanie Swan defined blockchain 1.0 to 3.0 based on the use scenarios that blockchain platforms are created to serve:
"Blockchain 1.0 is currency, the deployment of cryptocurrencies in applications related to cash, such as currency transfer, remittance, and digital payment systems.Blockchain 2.0 is contracts, the entire slate of economic, market, and financial applications using the blockchain that are more expensive than simple cash transactions: stocks, bonds, futures, loans, mortgages, titles, smart property, and smart contracts.Blockchain 3.0 is blockchain applications beyond currency, finance, and markets - particularly in the areas of government, health, science, literacy, culture, and art."
Some others divided blockchain evolution into four generations from blockchain 1.0 to 4.0:
- Blockchain 1.0: With Bitcoin being the most prominent example in this segment, use cases were based on the distributed ledger technology (DLT) where financial transactions could be executed. Cryptocurrency was used as cash for the Internet.
- Blockchain 2.0: With Ethereum being the most prominent example in this segment, the new key concept was Smart Contracts, which are stored and executed on a blockchain.
- Blockchain 3.0: The keyword is DApps, an abbreviation for decentralized applications, which avoided centralized infrastructure. They use decentralized storage and decentralized communication. Unlike a smart contract which only involves a backend or server-side code, a DApp can have frontend code and user interfaces, i.e. client-side code to interact with its backend code on a blockchain. Like the smart contract code, a DApp's frontend can be stored and executed on decentralized storage such as Ethereums Swarm. In summary, a DApp is frontend plus contracts running on Ethereum.
- Blockchain 4.0: Blockchain platforms in this segment are built to serve for Industry 4.0. Industry 4.0 refers, in a simple way, to automation, enterprise resource planning, and integration of different execution systems.
Regardless of how the blockchain technology is divided into versions, it is certain that the technology growth is far from being over. New ideas and implementations will be incorporated into the existing platforms to deal with challenges for real-life problems. In other words, blockchain technology will be nimble and is self-adjusted to be an enabler in resolving business problems.