An opcode (operation code) is a fundamental element of Bitcoin's scripting language. Opcodes determine how, where, and when transactions are processed on the blockchain. They are low-level operations that are often combined to create scripts for complex transactions.
"Opcodes like OP_CHECKSIG and OP_EQUALVERIFY are used in a standard Bitcoin transaction script to verify the transaction signature."
There are a variety of opcodes, each with a unique function. Some opcodes perform mathematical operations, some control the flow of execution, and others provide cryptographic functionality.
"The opcode OP_HASH160 is used to hash data with SHA-256 and then with RIPEMD-160, a common operation in Bitcoin address creation."
While the set of opcodes in Bitcoin's scripting language is mostly consistent, it can change during a hard fork, where opcodes can be added, removed, or modified.
"During the Bitcoin Cash hard fork in 2018, several previously disabled opcodes were re-enabled to expand the scripting capabilities of the network."
Understanding opcodes can be useful for developers working on Bitcoin or other similar blockchain protocols, as they provide the building blocks for transaction validation and smart contract functionality.
"By understanding opcodes, developers can create custom transaction types, enabling more complex use cases on the Bitcoin network."
* All terms and definitions may update as the Cryptionary improves.