Contracts keep ownership records; standards make them easier to use.
LET’S PICTURE IT
A ticket office has a register of owners. A token contract is a programmable register with agreed ways to read and update it.
SEE IT FOR YOURSELF
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.
ETH and tokens differ
ETH is the network’s native asset. An ERC-20 contract usually records interchangeable token balances. An ERC-721 contract tracks individually identified items, commonly called NFTs. Owning a token does not automatically give legal rights to an image, a company or a real object.
Why standards help
An ERC-20 interface includes functions such as balanceOf, transfer and approve. Wallets can recognize these common shapes. The ABI describes how to encode them. A familiar interface still does not prove that an implementation behaves honestly.
Raw numbers need context
transfer(address,uint256) takes a recipient and an integer in the token’s smallest units. A raw amount of 1000000 means one token if it uses six decimals, but 0.000000000001 tokens if it uses eighteen. Calldata alone does not include that display convention.
Allowances grant power
approve sets a spender’s allowance; transferFrom lets that spender move tokens under the contract’s rules. Inspect the spender and amount carefully. In the ABI lab, switch between transfer and approve to see how a similar pair of inputs can represent different permissions.