Put the shared notebook, its rules and its limits together.
LET’S PICTURE IT
Imagine your class shares a notebook of game points and checks each new page before treating it as part of the score.
SEE IT FOR YOURSELF
Link blocks, then see what an edit breaksStep 1 / 4
The first toy block records Maya sending Leo three units. A1 is an illustrative fingerprint label, not a real cryptographic digest.
The first toy block records Maya sending Leo three units. A1 is an illustrative fingerprint label, not a real cryptographic digest.Block two stores a reference to A1. A new page is connected to the prior page through its fingerprint.Block three refers to B2. The linked history now has three pages, each building on the previous one.Editing block one changes its toy fingerprint to X9. Block two still refers to A1, so its parent link is invalid and the downstream continuation needs revalidation.
Animated local teaching model. No wallet, RPC or live blockchain data. Some labels and hashes are abbreviated for readability.
The notebook is shared
A blockchain organizes a history into linked blocks. Many nodes can hold and check data. A copy of a notebook is not automatically authoritative merely because someone printed it; accepted rules and consensus context matter.
The links reveal edits
A parent hash connects a block with its predecessor. Editing covered data changes the fingerprint and breaks the old reference. Recalculating a toy chain on one computer is not enough to make Ethereum accept an invented history.
Programs add a shared rule system
Ethereum can execute smart contracts as part of transaction processing. Nodes check execution against the rules. Correct execution does not prove that outside-world claims supplied to a contract were truthful.
Public does not identify every person
Addresses help identify accounts, while the real-world person behind an account may require separate evidence. Public activity can still reveal links and patterns. Continue with exact units and wallet access to understand what users actually see.
QUICK CHECK · NO PRESSURE
What does a hash commitment establish by itself?
A hash commits to data; its meaning and trust context come from the surrounding system.