Glossary

Definitions of some technical terms used throughout the documentation.

Term	Meaning
EVM	Ethereum Virtual Machine
DeFi	Decentralized Finance
DB	Database
rdPoS	Random Deterministic Proof-of-Stake
RLP	Recursive-Length Prefix
BDK	Blockchain Development Kit
NFT	Non-Fungible Token
RPC	Remote Procedure Call
UTXO	Unspent Transaction Output (commonly used by Bitcoin-derived chains, analogous to Accounts, used by Ethereum-derived chains)
Secp256k1	The elliptic curve used for Bitcoin’s public key cryptography
Token table	A record of the token balances on each subnet, held by AppLayerLabs
Block race condition	A situation where multiple blocks compete for the position of the next block in the chain
Block congestion system	A component that manages the registration of blocks in the blockchain
RNG	Random Number Generator, a component in charge of making validator selection unpredictable
Master address	The address that adds validators to the network in a centralized implementation
Transpiler	A program that converts source code written in a specific programming language into its equivalent in another language
Constructor	A function that initializes the state variables of a contract
Pointer	An item that shows where data is stored and helps verify it
Sandbox	An isolated testing environment for experimenting with code
Merkle tree	An abstract data type with leaves (nodes) holding cryptographic hashes of data blocks while nodes that aren’t leaves have cryptographic hashes of their child nodes