The book has 354 pages. It has been written by Alex Mudly. This is an evident indication of the kind of information people are interested in. If we want to have for each book the same kind of description in order to compare the books, we will have to ask people to tell which picture is on the cover, to give the color of the cover, the year of publishing, the number of pages and the author. This list is a list of attributes .
Attributes contains atomic elements of information.
Grouped together the form the information entity . This information entity describes a book. An object can be in different states . For example a car can be riding or can be parked. A state is defined by setting conditions on descriptive elements of the objects.