Character Encoding
/ˈkærɪktər ɛnˈkoʊdɪŋ/
noun — "the method of representing characters as digital data."
Code
/kōd/
noun — "a system of symbols or rules used to represent information."
Code is a structured system for representing, communicating, or storing information using a defined set of symbols, rules, or conventions. In computing, cryptography, and digital communication, code refers to any method by which data or instructions are expressed in a form that can be transmitted, processed, or interpreted according to a predefined scheme. It emphasizes the *representation* of meaning rather than the meaning itself.
Operating System
/ˈɒpəreɪtɪŋ ˈsɪstəm/
noun — "software that governs hardware and programs."