O

object

(1) An internal structure that represents a system resource, such as a file, a thread, or a graphic image. See also thread.

(2) A network resource that does not contain any further network resources. It is not necessarily possible to connect to an object.

overlapped input and output (I/O)

See asynchronous input and output (I/O).

overlapped window

A style of window meant to serve as an application's main window.

owned window

A window that has an owner. Being owned affects the window's position in the Z order and its visibility and can determine when the window is destroyed.

owner window

A window that affects aspects of another window's appearance and behavior.

owner-drawn button

A button with the style BS_OWNERDRAW. Unlike all other button types, an owner-drawn button has no predefined appearance or behavior. Also, the application, not the system, is responsible for painting it. See also button.

owner-drawn control

A predefined control that sends messages to its parent window when it must be drawn.

owner-drawn item

A menu item whose appearance is controlled by a menu's owner window rather than by the system. See also menu item, window.