FOLLOW THE MECHANISM
- 1Contract
Stores balances or token ownership.
- 2Interface
Exposes recognizable functions to applications.
- 3Permission
May allow an approved spender to act.
- 4Transfer
Updates balances or ownership under implementation rules.
A conceptual sequence. Real implementations can add steps, intermediaries, and conditions.
A shared vocabulary for software
ERC-20 describes common functions and events for fungible tokens: balances, transfers and allowances. ERC-721 identifies distinct non-fungible tokens and their owners. ERC-1155 supports multiple token types within one contract, including batch operations. These standards allow wallets and applications to integrate known interfaces. They are Ethereum ecosystem examples; other networks have their own token systems, and an interface may have optional fields or implementation-specific behavior.
An allowance delegates spending authority
An ERC-20 holder can approve a spender to transfer up to a recorded allowance from the holder’s balance. The spender can then use the permitted transfer mechanism under the contract’s rules. Approval and actual transfer are different state changes. An allowance can persist after the website is closed. A very large allowance may expose future deposits as well as the tokens present when approval was first granted.
Metadata is not asset identity
A name, ticker and decimal display setting help interfaces show a token. They do not make a token unique or trustworthy: unrelated contracts can use the same symbol. The chain and contract address identify the implementation being used. Decimal places affect presentation of integer units; they do not create economic divisibility without limits or change the underlying amount. A visually familiar logo can therefore accompany a completely unrelated asset.
The implementation supplies extra rules
A token contract may allow minting, burning, pausing, freezing, transfer charges or upgrades. Some token behavior can surprise applications built around simpler assumptions. A standard interface is like a common shape for a connector: it improves compatibility, but it does not certify what is behind the connection. Understanding a token requires examining supply authority, transfer conditions and any claim on external assets in addition to recognizing its standard.
MAKE IT CONCRETE
Approval is not the purchase itself
Imagine a demonstration token balance of 100 units. Approving a contract for 60 leaves the balance at 100 while recording spending permission. If the contract later transfers 20 using that allowance, the balance can fall to 80 and the remaining allowance can fall to 40 in a conventional implementation. The two steps must not be confused.
FAILURE PATHS & COMMON MISREADINGS
Where the model can break
- A standard ticker is not a unique identifier.
- A familiar interface does not guarantee fixed supply or unrestricted transfers.
KEEP EXPLORING