attribute

In general, attributes are descriptive characteristics that can be assigned to a file, directory, or data field in a database. Thus, attributes can denote parameters that are required for the correct management of resources. The term attribute exists in various contexts; in file management, Internet terminology, encryption, graphics, X.500, and programming languages.

1. In file management, file attributes are used to identify files or directories. These attributes are assigned directly by the application program.
2. In markup languages such as HypertextMarkup Language( HTML), Extensible Markup Language(XML), or Standardized Generalized Markup Language( SGML), attributes are used in tags to define additional information to identify objects in more detail. Tags can have specific attributes to which corresponding values are assigned.
3. Attributes are also called user-configurable elements. This allows various program options to be set and the screen display of documents to be adapted to user requirements.
4. In programming languages, attributes are the properties of variables or of elements, as in SGML or XML.
5. The term attribute is also used in object-oriented programming( OOP). By it one understands a variable for the storage of object-specific data, which is assigned exactly to an object. The set of attributes of an object defines the object structure; the set of current attribute values defines the object state. Attributes of instance objects are also called instance variables, attributes of class objects accordingly class variables.
6. In multimedia, the properties of stimuli or sensation are characterized by attributes. Acoustic attributes include volume, pitch, tone, etc., and visual attributes include the hue, brightness, contrast, or chromaticity of a representation.
7. In X.500 terminology, this is the form of information provided by the X.500 Directory Service( DS). The Directory Information Base( DIB) consists of entries that include one or more attributes. Each attribute consists of a type identifier, along with one or more values. Attribute types are, for example, the name or the telephone or fax number.
8. In security concepts, an attribute represents an extension of the identification concept. This concept describes which activities a user may perform or which resources he may access.