Data

Data are representations of facts or observations used as a basis for reasoning, discussion, or computation. They are the raw inputs to information processing and, once interpreted, can become information, knowledge, or evidence. Data come in many forms, including numbers, text, images, audio, video, and sensor readings, and may be collected from experiments, transactions, observations, or automated systems. They are often stored in databases, data lakes, or files.

Categories of data include qualitative (categorical) data and quantitative (numerical) data; within quantitative data, discrete versus continuous; and structured versus unstructured data. Metadata, or data about data, describes its origin, context, and quality, aiding discoverability and reuse. Data quality refers to attributes such as accuracy, completeness, consistency, timeliness, and provenance. Data governance covers policies, standards, and stewardship to manage data assets across an organization. Data privacy and security address protection of sensitive information and control of access.

Data management involves collection, storage, processing, analysis, and dissemination. In practice, data are prepared and analyzed using statistical methods, machine learning, and visualization to extract insights. Open data initiatives promote public access to data, with licenses and norms for reuse. Ethical considerations include bias, accountability, and consent. Data stewardship emphasizes long-term preservation, versioning, and documentation to maintain data usefulness over time.