What is a fork?

The Ethereum blockchain is designed to run “smart contracts,” which are chunks of code that automatically execute a set of predetermined actions when certain criteria are met. Smart contract applications include everything from games to logistics tools to DeFi dapps. 

As the platform that runs all these applications, you can think of the Ethereum blockchain as similar to a computer’s operating system. In that analogy, the various Ethereum forks – Ethereum, Ethereum Classic, Ethereum 2.0 – are like newer versions of an operating system that add features or efficiencies the prior versions might have lacked. 

An older fork might continue as a stable, well-proven platform while a newer fork might offer developers entirely novel ways of interacting with it. (Older and newer versions can eventually merge or continue evolving further apart.)  

Think of a soft fork as a ‘software upgrade’ (like when your phone asks you to update to the latest OS) and a hard fork as an entire new operating system (like Linux and Mac OS are evolutions of the half-century old UNIX platform).