The **Display** APIs present the window layout of an application. The display attributes include the display ID, name, active status, state, refresh rate, rotation angle, width, height, pixel density, font scaling factor, and exact physical dots per inch.
## Basic Concepts
**Display**: a screen visible to an application. It can be used as a window container. It is an abstract concept that is different from a physical screen.
You can specify a display device to take screenshots, with screenshot parameters specified.
## Available APIs
For details about the APIs, see [Screenshot](../reference/apis/js-apis-screenshot.md).
## How to Develop
Call **save(options?: ScreenshotOptions): Promise<image.PixelMap>** to take a screenshot. In this API, **options** is a predefined screenshot parameter. If **options** is unspecified, the entire screen is captured by default. An example code snippet is as follows:
```js
importscreenshotfrom'@ohos.screenshot'// Import the module.
| moveTo(x: number, y: number): Promise\<void> | Moves the window position. A positive value of **x** indicates that the window moves to the right, and a positive value of **y** indicates that the window moves downwards.|
| destroy(): Promise\<void> | Destroys the window. |
## How to Develop
### Creating a Main Window
Currently, the main window is automatically created when the application is started. The declaration period, hiding, and destruction of the main window are managed by the application.
###Creating a Subwindow
You can call **create** to create a subwindow. The sample code is as follows:
```
import window from '@ohos.window';
var windowClass = null;
let promise = window.create("subWindow", window.WindowType.TYPE_APP);
console.error('Failed to find the Window. Cause: ' + JSON.stringify(err));
});
```
### Hiding and Destroying a Window
After a window object is obtained, you can call **hide** and **destroy** to hide and destroy the window object, respectively. The sample code is as follows:
The Window Manager subsystem provides basic capabilities of window and display management. It is the basis for UI display.
The Window Manager subsystem enables multiple applications to use the same physical screen for display and interaction. For each application, you only need to implement the interaction interface in the allocated display area. A window acts as a display container of the application interface, and the Window Manager subsystem organizes the interaction interfaces into a form visible to end users.
## Basic Concepts
**Immersive**
The colors of the application interface, status bar, and navigation bar are the same to achieve the visual integrity.
## Working Principles
To display a UI on a screen, the application and system need to request a window object from the Window Manager subsystem. This object generally represents a rectangular area on the screen and has attributes such as the position, width, height, and overlay layer. The object also loads the root node of the UI framework in the interface. The UI of the application is loaded and displayed in the window through the root node.
## Constraints
Except the **on** and **off** APIs used for callback subscription and unsubscription, all other window APIs are asynchronous interfaces.
