A "datum" is a single piece of information or a fact. It is the singular form of the word "data," which refers to multiple pieces of information. In various fields, such as science, statistics, and information technology, a datum can represent a measurement, observation, or any other specific detail that contributes to a larger analysis. In everyday use, a datum might be a number, a date, or a simple observation. For example, the temperature recorded at noon on a specific day is a datum. When many such data points are collected, they can be analyzed to identify trends or patterns, aiding in decision-making and research.