Data in everyday language is a synonym for information. In the exact sciences there is a clear distinction between data and information, where data is a measurement that can be disorganized and when the data becomes organized it becomes information. Data may relate to reality, or to fiction as in a fictional movie. Data about reality consists of propositions. A large class of practically important propositions are measurements or observations of a variable. Such propositions may comprise numbers, words or images.

Etymology
In English, the word datum is still used in the general sense of "something given", and more specifically in cartography, geography, geology, NMR and drafting to mean a reference point, reference line, or reference surface. The Latin plural data is also used as a plural in English, but it is perhaps more commonly treated as a mass noun and used in the singular, at least in day-to-day usage. For example, "This is all the data from the experiment". This usage is inconsistent with the rules of Latin grammar, which would suggest, "These are all the data from the experiment" instead; each measurement or result is a single datum. Many (perhaps most) academic, scientific, and professional style guides (e.g., see page 43 of the World Health Organization Style Guide) request that authors treat data as a plural noun.

Usage in English

Main article: Data (computing)