OGGlossary OSSolana vocabulary rebuilt for builders.
ENPT-BRES
Blockchain General

Mempool

The memory pool maintained by each blockchain node containing unconfirmed transactions that have been validated but not yet included in a block. Miners/validators select transactions from the mempool typically prioritizing those with the highest fee rate. Each node's mempool is independent and may differ based on propagation delays; during high-demand periods, the mempool can grow significantly, causing fee spikes as users compete for limited block space.

IDmempoolAliasMemory PoolAliasTransaction Pool
Plain meaning

Plain meaning

Start with the shortest useful explanation before going deeper.

The memory pool maintained by each blockchain node containing unconfirmed transactions that have been validated but not yet included in a block. Miners/validators select transactions from the mempool typically prioritizing those with the highest fee rate. Each node's mempool is independent and may differ based on propagation delays; during high-demand periods, the mempool can grow significantly, causing fee spikes as users compete for limited block space.

Mental model

Mental model

Use the quick analogy first so the term is easier to reason about when you meet it in code, docs, or prompts.

Think of it as a building block that connects one definition to the larger Solana system around it.

Technical context

Technical context

Place the term inside its Solana layer so the definition is easier to reason about.

Shared crypto concepts that frame the broader ecosystem.

Why builders care

Why builders care

Turn the term from vocabulary into something operational for product and engineering work.

This term unlocks adjacent concepts quickly, so it works best when you treat it as a junction instead of an isolated definition.

AI handoff

AI handoff

Use this compact block when you want to give an agent or assistant grounded context without dumping the entire page.

Mempool (mempool)
Category: Blockchain General
Definition: The memory pool maintained by each blockchain node containing unconfirmed transactions that have been validated but not yet included in a block. Miners/validators select transactions from the mempool typically prioritizing those with the highest fee rate. Each node's mempool is independent and may differ based on propagation delays; during high-demand periods, the mempool can grow significantly, causing fee spikes as users compete for limited block space.
Aliases: Memory Pool, Transaction Pool
Related: Bitcoin, Proof-of-Work Mining, Transaction Fee
Glossary Copilot

Ask grounded Solana questions without leaving the glossary.

Use glossary context, relationships, mental models, and builder paths to get structured answers instead of generic chat output.

Open full Copilot workspace
Explain this code

Optional: paste Anchor, Solana, or Rust code so the Copilot can map primitives back to glossary terms.

Ask a glossary-grounded question

Ask a glossary-grounded question

The Copilot will answer using the current term, related concepts, mental models, and the surrounding glossary graph.

Concept graph

See the term as part of a network, not a dead-end definition.

These branches show which concepts this term touches directly and what sits one layer beyond them.

Branch

Bitcoin

The first decentralized cryptocurrency network, launched in 2009 by the pseudonymous Satoshi Nakamoto, using a Proof-of-Work consensus mechanism and a UTXO-based transaction model. Bitcoin's protocol enforces a fixed supply cap of 21 million BTC, with new coins issued through mining block rewards that halve approximately every four years. It serves as both a peer-to-peer electronic cash system and a store of value, with its scripting language enabling basic programmability such as multisig and timelocks.

Proof of Work (PoW)UTXO Model
Open term
Branch

Proof-of-Work Mining

The process by which miners expend computational resources to find a nonce producing a block header hash below the current difficulty target, earning the right to append a new block and collect the block reward plus fees. Bitcoin mining uses SHA-256d (double SHA-256) and adjusts difficulty every 2,016 blocks (~2 weeks) to maintain ~10-minute block times. Mining has evolved from CPUs to GPUs to ASICs, with industrial-scale operations dominating the network's hash rate.

Bitcoin Halving
Open term
Branch

Transaction Fee

The cost paid by the sender to have a transaction processed and included in a block. Fees compensate validators/miners for computation and prevent spam. Fee models vary: Ethereum uses dynamic gas pricing (EIP-1559 base fee + tip), Solana uses base fee (5,000 lamports) + optional priority fee, Bitcoin uses fee-per-byte.

GasPriority Fee
Open term
Next concepts to explore

Keep the learning chain moving instead of stopping at one definition.

These are the next concepts worth opening if you want this term to make more sense inside a real Solana workflow.

Blockchain General

Bitcoin

The first decentralized cryptocurrency network, launched in 2009 by the pseudonymous Satoshi Nakamoto, using a Proof-of-Work consensus mechanism and a UTXO-based transaction model. Bitcoin's protocol enforces a fixed supply cap of 21 million BTC, with new coins issued through mining block rewards that halve approximately every four years. It serves as both a peer-to-peer electronic cash system and a store of value, with its scripting language enabling basic programmability such as multisig and timelocks.

Open term
Blockchain General

Proof-of-Work Mining

The process by which miners expend computational resources to find a nonce producing a block header hash below the current difficulty target, earning the right to append a new block and collect the block reward plus fees. Bitcoin mining uses SHA-256d (double SHA-256) and adjusts difficulty every 2,016 blocks (~2 weeks) to maintain ~10-minute block times. Mining has evolved from CPUs to GPUs to ASICs, with industrial-scale operations dominating the network's hash rate.

Open term
Blockchain General

Transaction Fee

The cost paid by the sender to have a transaction processed and included in a block. Fees compensate validators/miners for computation and prevent spam. Fee models vary: Ethereum uses dynamic gas pricing (EIP-1559 base fee + tip), Solana uses base fee (5,000 lamports) + optional priority fee, Bitcoin uses fee-per-byte.

Open term
Blockchain General

Merkle Tree

A binary tree where each leaf node is a hash of data and each internal node is the hash of its two children. The root hash (Merkle root) uniquely represents all underlying data. Merkle trees enable efficient proof of inclusion—proving a specific element exists requires only O(log n) hashes. Used in blockchains for transaction verification and state storage.

Open term
Commonly confused with

Terms nearby in vocabulary, acronym, or conceptual neighborhood.

These entries are easy to mix up when you are reading quickly, prompting an LLM, or onboarding into a new layer of Solana.

Blockchain Generalmainnet

Mainnet

The production blockchain network where real-value transactions occur. Solana's production network is 'mainnet-beta'. Deploying to mainnet requires thorough testing on devnet/testnet, security audits for significant programs, and careful consideration of upgrade authority management. Mainnet state is permanent and transactions involve real financial value.

Open term
Blockchain Generalshielded-transaction

Shielded Transaction

A Zcash transaction where sender address, receiver address, and amount are encrypted using zk-SNARKs, providing cryptographic privacy while allowing network nodes to verify validity without learning private details. Shielded transactions operate within dedicated value pools (Sapling or Orchard), each with independent circuit designs. Users can selectively disclose transaction details to third parties using viewing keys without compromising spending authority.

AliasPrivate Transaction (Zcash)
Open term
Blockchain Generalblob-transaction

Blob Transaction (EIP-4844)

An Ethereum transaction type introduced in the Dencun upgrade (March 2024) that carries binary large objects (blobs) of temporary off-chain data. Each blob is 128 KB, committed via KZG polynomial commitments, and stored for ~18 days before pruning. Blob transactions created a separate fee market and reduced Layer 2 rollup fees by 10-100x by providing cheap, temporary data availability.

AliasBlobAliasEIP-4844
Open term
Related terms

Follow the concepts that give this term its actual context.

Glossary entries become useful when they are connected. These links are the shortest path to adjacent ideas.

Blockchain Generalbitcoin

Bitcoin

The first decentralized cryptocurrency network, launched in 2009 by the pseudonymous Satoshi Nakamoto, using a Proof-of-Work consensus mechanism and a UTXO-based transaction model. Bitcoin's protocol enforces a fixed supply cap of 21 million BTC, with new coins issued through mining block rewards that halve approximately every four years. It serves as both a peer-to-peer electronic cash system and a store of value, with its scripting language enabling basic programmability such as multisig and timelocks.

Open term
Blockchain Generalproof-of-work-mining

Proof-of-Work Mining

The process by which miners expend computational resources to find a nonce producing a block header hash below the current difficulty target, earning the right to append a new block and collect the block reward plus fees. Bitcoin mining uses SHA-256d (double SHA-256) and adjusts difficulty every 2,016 blocks (~2 weeks) to maintain ~10-minute block times. Mining has evolved from CPUs to GPUs to ASICs, with industrial-scale operations dominating the network's hash rate.

Open term
Blockchain Generaltransaction-fee-general

Transaction Fee

The cost paid by the sender to have a transaction processed and included in a block. Fees compensate validators/miners for computation and prevent spam. Fee models vary: Ethereum uses dynamic gas pricing (EIP-1559 base fee + tip), Solana uses base fee (5,000 lamports) + optional priority fee, Bitcoin uses fee-per-byte.

Open term
More in category

Stay in the same layer and keep building context.

These entries live beside the current term and help the page feel like part of a larger knowledge graph instead of a dead end.

Blockchain General

Blockchain

A distributed, append-only ledger that records transactions in cryptographically linked blocks. Each block contains a hash of the previous block, forming an immutable chain. Nodes in the network maintain copies of the ledger and reach agreement through consensus mechanisms. Blockchains enable trustless, decentralized record-keeping without a central authority.

Open term
Blockchain General

Consensus Mechanism

The protocol by which nodes in a distributed network agree on the current state of the ledger. Common mechanisms include Proof of Work (Bitcoin), Proof of Stake (Ethereum, Solana), and BFT variants. Consensus ensures all honest nodes converge on the same transaction history despite potential network delays or malicious actors.

Open term
Blockchain General

Proof of Stake (PoS)

A consensus mechanism where validators are selected to produce blocks based on the amount of cryptocurrency they have staked (locked) as collateral. PoS is energy-efficient compared to Proof of Work. Misbehaving validators risk losing their stake (slashing). Solana, Ethereum (post-Merge), Cosmos, and Cardano use PoS variants.

Open term
Blockchain General

Proof of Work (PoW)

A consensus mechanism where miners compete to solve computationally expensive puzzles to produce blocks and earn rewards. PoW provides strong security (51% attack resistance) but is energy-intensive. Bitcoin and pre-Merge Ethereum use PoW. The difficulty adjusts to maintain target block times regardless of total network hash power.

Open term