(1) A characteristic. In a word processing application, an underlined word would be said to have the underline attribute. In database systems, a field can have various attributes. For example, if it contains numeric data, it has the numeric attribute.
(2) In database management systems, the term attribute is sometimes used as a synonym for field.
(3) In DOS systems, every file has a file attribute that indicate several properties of the file. For example, they indicate whether the file is read-only, whether it needs to be backed up, and whether it is visible or hidden.
(4) A language construct that programmers use to add additional information (i.e., metadata) to code elements (e.g., assemblies, modules, members, types, return values, and parameters) to extend their functionality.