Opcode
An opcode, derived from “operation code,” refers to a set of low-level programming instructions that are easily comprehensible to humans. Specifically within the Ethereum ecosystem, opcode represents a collection of 140 unique commands executable by the Ethereum Virtual Machine (EVM). Acting as the environment and rule-set for Ethereum smart contracts and accounts, the EVM facilitates their execution. While it is technically possible to write programs directly using opcode, this approach is notably more challenging compared to utilizing a high-level language like Solidity. Examples of fundamental opcode commands include ‘PUSH’ and ‘POP’, which respectively enable the addition and removal of data within the EVM.