A measure of how hard it is to find a proof-of-work hash that meets the network’s target.
Difficulty helps keep block production near the network's intended average as miners join or leave. Bitcoin adjusts its target periodically based on earlier block timing. It concerns the required hash result, not how complicated the transactions are; a block full of simple payments still needs valid proof of work.
IN THE WILD
'More miners joined, but blocks aren't meant to stay faster forever.' Bitcoin's next difficulty adjustment responds to the preceding block timing.
A group of miners that coordinates work and shares rewards using an agreed payout scheme.
Finding a block alone can mean a long wait between payouts. Pools combine participating miners' work so rewards can be distributed more regularly, according to the pool's rules. The coordinator often influences which transactions go into candidate blocks, so pool organization matters as well as raw computing power.
IN THE WILD
A small miner submits work shares to a pool and receives payouts under that pool's scheme instead of waiting to find a block alone.
An authorization arrangement that requires signatures from a specified number of distinct keys.
A two-of-three setup needs two of its three authorized keys to sign. This spreads control and can allow one missing signer. Who holds each key, how independent they are and how recovery works determine practical security; three keys on one compromised device provide little separation.
IN THE WILD
Treasury chat: "One signature is in. We need one more from our two-of-three signer set before this payment can go out."
Descriptive data linked to an NFT, such as its name, attributes and media references.
The token identifies the item, while metadata often supplies what a marketplace displays about it. This can live onchain or come from an external location. The contract and storage arrangement determine whether it can change and whether the referenced media remains available, rather than the NFT label deciding those details.
IN THE WILD
"Why does the marketplace show those traits?" The NFT's metadata JSON supplies its name, attributes and image reference.
A computer or software instance participating in a blockchain network.
People sometimes use 'node' as though every node does the same job. In practice, it might relay transactions, validate blocks, answer wallet queries or help produce blocks. These roles depend on the network and configuration. A node isn't automatically a miner, a validator or a complete archive.
IN THE WILD
Your wallet connects to a node for balance information; that node can also relay your signed transaction to its peers.
A token with an individual identity rather than interchangeable units, commonly called an NFT.
An NFT lets a chain track a particular token, which might represent artwork, a membership or a game item. Owning that token is different from owning copyright or controlling the file it points to. Look at the project's actual terms and how its metadata is stored before assuming what the token gives you.
IN THE WILD
“I bought the NFT—can I sell prints?” Token ownership alone doesn’t answer that; you check the rights attached to the artwork.
A basic instruction understood by a virtual machine or scripting system.
At the machine level, a contract is a sequence of small instructions: add values, read data, store a value or call other code. These are opcodes. In the EVM they have defined behavior and gas costs, which helps explain why two functions with similar-looking buttons can require different amounts of work.
IN THE WILD
An EVM trace shows an ADD instruction combining two values, followed by instructions that store the result.
A rollup that accepts submitted execution results subject to a process for challenging invalid results.
Optimistic here describes how a submitted result is treated, not an expectation that token prices rise. Results can be disputed during a defined window using the protocol's challenge mechanism. Available data and effective challengers are important, and standard withdrawals may need to wait for that dispute window to end.
IN THE WILD
A challenger spots an incorrect state update and disputes it while the optimistic rollup's challenge window is still open.
A mechanism that supplies information a blockchain application cannot directly obtain for itself.
A lending contract can read its own balances, but needs help knowing an asset's price elsewhere. An oracle brings that information into the system. Useful questions are where the data comes from, how it is checked and how recent it is when the contract uses it.
IN THE WILD
"I haven't borrowed more, but my collateral ratio changed after the oracle updated the price of my ETH."
Influencing data an application treats as an authoritative input, such as its collateral price.
A contract can execute exactly as written and reach a bad result if its price input is distorted. A thin pool's momentary price is one possible weak point. Feed sources, update rules and consumer checks determine how much a temporary market move can affect the application.
IN THE WILD
The lending app reads a thin pool's price just as an attacker distorts it, giving the collateral a misleading valuation.
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.