CUA guidelines defined the user interface for application-oriented environments. In object-oriented environments, such as the OS/2 operating system, the user performs tasks by manipulating on-screen objects. The user does not start an application to perform a task. Instead, the user can do the following:

• Select an action or task that can be performed on an object. For example, the user selects the Open action on an ASCII file object. The operating system then starts an editor to work on the file.

• Select the Open action on a spreadsheet file. The operating system then starts a spreadsheet application to work on the file.

• Drag the ASCII file object to a printer object and drop it on the printer object. The file is then sent to the printer.

The concept of applications is transparent to the user. The user interacts with objects rather than with the operating system or with separate applications. The user focuses on the task and not on the tools used to perform the task. The user interacts with objects in the same manner across tasks.