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 <index>, while the name of a window source will match the window title.
thumbnail NativeImage - 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 returned by the Screen API. 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 - 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.