annotation

This term describes the act of adding supplementary information to a primary source to clarify, critique, or categorize it. In literary and academic contexts, it serves as a bridge between the original text and the reader's understanding, often appearing as footnotes or marginalia. In modern technical fields, the word has shifted toward data labeling. In machine learning, it refers to the process of assigning ground-truth labels to raw data, while in programming, it denotes non-executable metadata that provides instructions to the compiler or other developers.