Recently, I've delved into discussions about public blockchain technology and would like to document my learning outcomes.

Founder, zCloak Network. 
Building a ZKP-powered Self-Sovereign Identity Network. 

"Consensus" refers to the ability to compute based on the immutable data on the blockchain (state transition) and obtain results (such as transferring funds or executing smart contracts). "Cognition" denotes the ability for the outcomes of the blockchain's computation to be obtained and perceived by common users.

There is a hierarchical relationship among these three: facts determine consensus, and consensus determines cognition; consensus stems from the computation of facts, while cognition comes from the transmission and perception of consensus.

I guess for the majority of ordinary users, what they care most about is simple and easily obtained cognition (What is my account balance? Was this transaction successful?).

Following this line of thought, I believe that the various "blockchain systems" widely discussed recently can generally be categorized into three types (based on their features):

1. Systems like Ordinals, Arweave AO, and Bitcoin RGB, which provide facts but do not offer consensus. To achieve consensus, users must figure it out by themselves (by running their own off-chain indexer, resolving disagreements among multiple indexers, etc.).

2. Public blockchains like Bitcoin, Ethereum and Solana, which provide facts and consensus but do not offer easily obtainable cognition. To attain cognition, users must either run a full node themselves or trust those who do so (e.g. RPC service). A slight upgrade from full nodes are light nodes and zk coprocessors.

3. ICP (Internet Computer Protocol), which provides facts, consensus, and easily obtainable cognition. To obtain any computational result on the blockchain with certainty, one does not need to run any nodes or trust any intermediaries—they simply verify a digital signature.

The public key for this digital signature corresponds to the public key of a certain "smart contract" on ICP (ICP's smart contract, the canister, has the capability to sign any information with threshold ECDSA).

From the perspective of user experience and cognition, the friendliness of the three systems mentioned above increases progressively, which also reflects the development trajectory of the industry.

The services that blockchain systems can provide to users can be divided into three levels: fact, consensus, and cognition. By "fact," we mean the ability for anyone to write immutable data onto the blockchain (i.e., to make a transaction).