Data is stored in a computer in different data types. Numbers are stored in integers or real numbers, text is stored in strings and pictures in graphical formats.
Development environments like Scratch, Greenfoot, App Inventor and Visual Basic make extensive use of graphical objects. It is possible to add graphical objects to the interface.
Programmers can then use code to alter the properties of these objects so that they can perform actions. Examples of some properties that can be altered are:
set the height and width of a graphic
display it in front or behind other objects
set where on the screen it is displayed
make something happen when it is clicked on or a mouse pointer moves over it
