**Data** (singular: **datum**) are individual units of [[Information|information]], often collected through [[Observation|observation]], [[Experiment|experimentation]], or [[Measurement|measurement]]. In common usage and across many disciplines, data refers to a collection of [[Fact|facts]], [[Statistics|statistics]], or values that can be analyzed, interpreted, or processed to derive meaning. Data is a foundational concept in fields including [[Science|science]], [[Mathematics|mathematics]], [[Computer science|computer science]], [[Economics|economics]], and [[Business|business]], and is central to modern [[Information technology|information technology]] and [[Decision-making|decision-making]] processes. Data can be classified in several ways. By structure, it is commonly categorized as [[Structured data|structured]] (organized in fixed formats such as [[Database|databases]] and [[Spreadsheet|spreadsheets]]), [[Semi-structured data|semi-structured]] (partially organized, as in [[XML]] or [[JSON]]), or [[Unstructured data|unstructured]] (lacking a predefined format, such as [[Free text|text]], [[Digital image|images]], and [[Digital audio|audio]]). Data may also be described as [[Qualitative data|qualitative]] or [[Quantitative data|quantitative]], and as [[Raw data|raw]] (unprocessed) or [[Data processing|processed]]. The relationship between data, information, and [[Knowledge|knowledge]] is often represented through the [[DIKW pyramid]], in which data serves as the base layer that, when contextualized and interpreted, becomes information and ultimately knowledge. The collection, storage, and use of data have grown exponentially since the advent of [[Digital computing|digital computing]] and the [[Internet|internet]], giving rise to the era of [[Big data|big data]]. This growth has driven the development of disciplines such as [[Data science|data science]], [[Data engineering|data engineering]], and [[Data analytics|data analytics]], as well as technologies including [[Data warehouse|data warehouses]], [[Data lake|data lakes]], and [[Machine learning|machine learning]] systems. The proliferation of data has also raised significant concerns regarding [[Data privacy|data privacy]], [[Data security|data security]], [[Data ethics|data ethics]], and [[Data sovereignty|data sovereignty]], prompting regulatory frameworks such as the [[General Data Protection Regulation]] in the [[European Union]] and the [[California Consumer Privacy Act]] in the [[United States]].