A record of who owns what, or what changed, kept as data.
LET’S PICTURE IT
Your class library has a list of borrowed books. That list is a ledger: it records changes so people can work out the current situation.
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.
Records answer questions
A ledger can record “Maya borrowed book 7” and later “Maya returned book 7.” The list lets you work out who has the book now. A digital ledger stores similar records in computer-readable form. It need not involve cryptocurrency or a blockchain.
Who gets to update it?
In a school library, one librarian might control the record. Other people trust that librarian to record changes accurately. In a shared blockchain ledger, participants instead use agreed validation rules and a mechanism for choosing the accepted sequence.
History and current state
History tells you the sequence of changes. Current state tells you the result after applying them. A balance is state; the transfers that explain it are history. Confusing those two can make a block explorer look more mysterious than it really is.
Connect the idea
A blockchain is one way of organizing a shared ledger. It adds blocks, hash links and consensus rules. Next, ask why multiple computers need to agree when they receive updates in different orders.
QUICK CHECK · NO PRESSURE
Is every digital ledger a blockchain?
A blockchain is a particular design for a ledger. Ordinary databases can keep ledgers too.