Holochain is not a blockchain. It's more like "git repositories for each agent which can be published, shared, synchronized or merged via a BitTorrent-like DHT (Distributed Hash Table)". This shift to 'agent-centrism' rather than 'data-centrism' is important. Each application has its own Holochain, and each agent has their own chain. Rather than spending an absurd amount of energy to craft a single record of events, Holochain allows people to write anything to their own chain. However, transactions that violate the rules of the application (such as me saying that you gave me all your tokens) won't be propagated by the network.
What does this mean to real people? Well, imagine Facebook without Zuckerburg sucking up all the wealth. Users get paid for their posts and for the data they generate - if they opt in to their data being sold. Imagine Uber owned by the drivers and riders; AirBnb owned by the hosts and guests. Strangers can interact collaboratively in a high-trust manner, without a profit-seeking corporation sucking up all of the ‘value’ it can.
Holochain is not just a way of verifying and controlling data. It is also a way of hosting that data as well: Ethereum meets the Inter-Planetary File System. When a request is made to see new messages on Holochain’s Twitter-killer, Clutter, the data is sourced from nearby nodes and comes in gradually like flowing water rather than being delivered in a single dump from a centralized database.
When you add something to a holochain, you sign it, append it to your own chain (like in Hashgraph, the latest entry is hashed to confirm the whole history is valid), and submit it to the Distributed Hash Table, which makes sure it conforms to that chain’s rules. You are also receiving and checking other people's transactions in the process. Each application is its own Holochain, and a cell phone can easily act as a node for multiple Holochain apps.
