DesktopCapturerSource Object 
- idstring - The identifier of a window or screen that can be used as a- chromeMediaSourceIdconstraint when calling- navigator.getUserMedia. The format of the identifier will be- window:XX:YYor- 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.
- namestring - A screen source will be named either- Entire Screenor- Screen <index>, while the name of a window source will match the window title.
- thumbnailNativeImage - A thumbnail image. Note: There is no guarantee that the size of the thumbnail is the same as the- thumbnailSizespecified in the- optionspassed to- desktopCapturer.getSources. The actual size depends on the scale of the screen or window.
- display_idstring - A unique identifier that will correspond to the- idof the matching Display returned by the Screen API. On some platforms, this is equivalent to the- XXportion of the- idfield above and on others it will differ. It will be an empty string if not available.
- appIconNativeImage - 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.