Ethereum’s protocol-set execution fee per gas unit, which adjusts with block demand and is burned.
The base fee is the part of an Ethereum execution fee determined by the protocol. It changes as blocks fill above or below their target usage, so yesterday's quote isn't today's promise. This part is burned rather than paid to the block proposer; a priority fee is a separate component.
IN THE WILD
Your wallet’s maximum fee no longer covers the rising base fee, so the transaction waits until it can be included or you replace it.
An address encoding with error detection, introduced for native SegWitBitcoin outputs.
A Bech32 address has a readable prefix and a checksum designed to catch typing mistakes. Bitcoinmainnet SegWit version-zero addresses commonly start with bc1q. Later witness versions use Bech32m, a related encoding. Recognizing the prefix is useful, but it doesn't establish who controls the address you're about to use.
IN THE WILD
A friend sends you a bc1q address. Your wallet checks its format and checksum before preparing the Bitcoin payment.
A price at which a participant or trading system is prepared to buy an asset.
The best displayed bid is the highest visible buying price in an order book. It comes with an available quantity, so selling more than that amount can reach lower bids. This explains why reading only the top price does not fully describe the proceeds of a larger sale.
IN THE WILD
The best bid is 99 for two units; selling more than two may also match lower bids in the book.
The gap between the best available buying and selling prices in a market.
The spread separates the price immediately available to a seller from the price immediately available to a buyer. It often widens in thin or unsettled markets and is one part of trading cost. Fees and price movement can add more, while some platforms use spread for a separate pricing charge.
IN THE WILD
You see a 99 best bid and 101 best ask: immediately selling and immediately buying start on opposite sides of that 2-point spread.
Bitcoin’s stack-based programming language for defining the conditions needed to spend transaction outputs.
A Bitcoin output can require more than 'show one signature.' Script lets it express conditions involving multiple signatures or time constraints. The language has a deliberately limited execution model, unlike general-purpose smart-contract environments. Those conditions are what nodes check when someone later tries to spend the output.
IN THE WILD
A shared treasury output uses Bitcoin Script to require signatures from two designated keys before the BTC can move.
A specialized Ethereum data payload with a separate fee market and temporary availability rules, used by systems such as rollups.
Blobs give rollups a place to publish data without putting the whole payload into ordinary EVM execution. Their data is distributed through Ethereum's consensus mechanisms, while contracts do not directly read the full blob contents. The retention rules matter: applications needing older data must account for its temporary network availability.
A batch of blockchain data that is accepted as one step in the network’s history.
Your transaction usually travels alongside other transactions in a block. Nodes check that the proposed block follows the protocol before accepting it, including its connection to earlier history. A producer finding or proposing a block doesn't get to sneak an invalid payment past those checks.
IN THE WILD
An explorer shows several transactions inside one block. A node rejects that whole proposed block if it breaks a consensus rule.
An explorer makes raw chain activity easier to search and read. It may add labels, decoded calls and other interpretations alongside the underlying records. Those additions are not themselves consensus facts. The selected network and the explorer's indexing progress can explain why two views show different information.
IN THE WILD
"Did that swap actually go through?" You paste its transaction ID into an explorer to inspect the execution result and logs.
A compact set of block fields used to identify the block and check important validity requirements.
On Bitcoin, the header includes the previous block's hash, a summary of its transactions called the Merkle root, timing information and proof-of-work fields. Changing the transaction set changes that summary and the header hash. A header is useful for compact checks, but isn't the full transaction data.
IN THE WILD
A miner changes the transactions in its candidate block. The Merkle root changes, so it must work with a different header hash.
A block’s numbered position in a chain, counted from the first block.
Height is useful when people discuss upgrades, timelocks or how far a node has synced. Bitcoin starts at height zero. A height isn't a unique identity, though: two competing branches can each have a different block at the same height. The block hash tells you which one.
IN THE WILD
'My node is a few hundred blocks behind.' Comparing its block height with the network's current height shows the gap.
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.