# DesktopCapturerSource Object * `id` string - The identifier of a window or screen that can be used as a `chromeMediaSourceId` constraint when calling [`navigator.webkitGetUserMedia`]. The format of the identifier will be `window:XX:YY` or `screen:ZZ:0`. XX is the windowID/handle. YY is 1 for the current process, and 0 for all others. ZZ is a sequential number that represents the screen, and it does not equal to the index in the source's name. * `name` string - A screen source will be named either `Entire Screen` or `Screen `, while the name of a window source will match the window title. * `thumbnail` [NativeImage](../native-image.md) - A thumbnail image. **Note:** There is no guarantee that the size of the thumbnail is the same as the `thumbnailSize` specified in the `options` passed to `desktopCapturer.getSources`. The actual size depends on the scale of the screen or window. * `display_id` string - A unique identifier that will correspond to the `id` of the matching [Display](display.md) returned by the [Screen API](../screen.md). On some platforms, this is equivalent to the `XX` portion of the `id` field above and on others it will differ. It will be an empty string if not available. * `appIcon` [NativeImage](../native-image.md) - An icon image of the application that owns the window or null if the source has a type screen. The size of the icon is not known in advance and depends on what the application provides.