A token ID distinguishes an item within its contract’s collection.
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Two library books can have separate inventory IDs even if their cover art looks the same.
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A valid counter call, step by stepStep 1 / 4
This example begins with count zero and a request to call increment(). No real contract is deployed.
This example begins with count zero and a request to call increment(). No real contract is deployed.Execution follows the code’s input and permission rules. A website button is not the access-control mechanism.The function reads zero, calculates zero plus one, and writes one to persistent storage.The accepted state contains count one. Later reads can inspect it. Events are emitted only if the code implements them.
Animated local teaching model. No wallet, RPC or live blockchain data. Some labels and hashes are abbreviated for readability.
Identity has multiple parts
An ERC-721 item is identified in its contract by a token ID. Network, contract address and token ID together supply the useful onchain context. Token ID 7 in another collection is a different item.
Unique does not mean one image
Two tokens can refer to the same media or similar metadata. Non-fungibility concerns individually tracked token identity and ownership, not proof that the artwork has never appeared elsewhere.
Rights need a separate basis
Holding a token does not automatically grant copyright, ownership of a physical object or every commercial right. Those claims depend on additional terms and mechanisms beyond the bare ownership record.
Read the ownership rules
The contract determines how ownership and approvals change. A marketplace image is a presentation layer. Learn ERC-721 ownership and metadata separately so each claim has the right evidence.
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Is token ID 7 globally unique across every NFT contract?