The part of a Bitcointransaction that assigns value and specifies the conditions for spending it.
Outputs answer 'where does the value go, and how can it be spent next?' An output that remains unspent is a UTXO. A normal payment may create one output for the recipient and another for change, so seeing multiple outputs doesn't necessarily mean you paid multiple people.
IN THE WILD
'Why are there two outputs?' One sends BTC to your friend; the other returns the unused value to your wallet.
A record of an included Ethereumtransaction’s execution result, including status, gas use and logs.
A receipt tells you what happened after a transaction was included, rather than merely confirming that you submitted it. The status can show success or failure, and the gas information helps explain the fee. A failed transaction can have a receipt too. Inclusion should still be considered alongside the chain's settlement or finality state.
IN THE WILD
Your explorer receipt shows a failed swap and its gas usage, explaining why no tokens moved but a network fee was charged.
A preview of transaction execution against a chosen blockchain state before the transaction is settled.
Simulation turns a contract call into a readable preview, such as expected balance changes or a likely error. It runs against a particular view of the chain. Prices or execution conditions may change before inclusion, so a useful simulation remains a preview rather than a promise.
IN THE WILD
Before you sign, your wallet previews the tokens expected to leave and arrive; the transaction has not settled yet.
Total value locked: an estimate of the monetary value of assets deposited in a protocol or category.
TVL gives a rough picture of deposited value, but the number depends on asset prices and the provider's counting method. It can rise without new deposits if token prices rise, and some calculations can count linked positions more than once. It isn't a direct measure of users, revenue, available trading liquidity or security.
IN THE WILD
A dashboard’s TVL rises after ETH’s price increases, even though the protocol received no additional ETH deposits during that period.
Signing structured Ethereum messages using a format such as EIP-712.
Typed data gives fields names and types, and adds domain information identifying the signing context. This can make a permit or another authorization easier to inspect than raw bytes. It improves representation, but a neatly formatted message can still grant permission you did not intend to give.
IN THE WILD
Your wallet displays the spender, amount and deadline as readable EIP-712 fields instead of presenting only opaque bytes.
A token-spending permission set to a very large allowance rather than the amount needed for one action.
Apps may request this to avoid another approval transaction each time you return. Permission stays tied to one token and spender, but can expose more of that token balance than today's swap needs. The trade-off is fewer approvals against broader access if that spender becomes malicious or compromised.
IN THE WILD
"I'm swapping 20 tokens, but the approval request covers far more than this swap."
An ERC-4337 data structure describing an operation requested by a smart account.
A UserOperation is a request that enters the ERC-4337 account-abstraction flow. A bundler can include it in an onchain transaction through the EntryPoint contract, which checks the relevant rules. It has its own processing steps, so a pending operation isn't simply the same thing as a normal transaction already submitted to Ethereum.
The proportion of a lending pool’s supplied liquidity that is currently borrowed.
Utilization tells you how much of a pool's available capital borrowers are using. Many lending models raise borrowing rates as utilization rises, but the exact calculation follows the protocol's accounting. High utilization can also mean less immediately available liquidity for withdrawals, so a healthy deposit balance isn't always the same as cash ready to leave.
IN THE WILD
Borrowing demand rises in a lending pool, pushing utilization up and leaving less unborrowed liquidity for suppliers to withdraw immediately.
Bitcoin doesn't keep your wallet balance as one editable account number. Your wallet adds up spendable outputs, a bit like separate pieces of value it can combine. Spending consumes whole outputs and can create new ones for the recipient and your change. Each output is spendable once in the accepted chain.
IN THE WILD
You have two UTXOs worth 0.004 BTC each. Your wallet uses both to fund a 0.006 BTC payment and creates change after the fee.
A participant that performs consensus duties such as checking, proposing or voting on blocks.
A validator helps the network agree on valid history, but its exact job depends on the protocol. On Ethereum, duties include proposing blocks when selected and sending attestations. Being offline can lose rewards or incur penalties, while specified conflicting behavior can be slashable. Running the software reliably is part of the job.
IN THE WILD
Your validator dashboard reports missed attestations after an internet outage, so you check the connection before looking only at the reward estimate.
The daily pick rotates automatically. Our initial collection was published on October 9, 2026. New words join on their publication date. Every concept includes a reference.