What is "object" in FlyViewMap.qml

Hi. I’m new to QML and am looking through the source code for QGC. I’m trying to add visual elements to the map given the coordinates. Currently I’m looking at FlyViewMap.qml for inspiration and found these arbitrarily named objects starting at around line 255:

    // Add the vehicles to the map
    MapItemView {
        model: QGroundControl.multiVehicleManager.vehicles
        delegate: VehicleMapItem {
            vehicle:        object
            coordinate:     object.coordinate
            map:            _root
            size:           pipMode ? ScreenTools.defaultFontPixelHeight : ScreenTools.defaultFontPixelHeight * 3
            z:              QGroundControl.zOrderVehicles
        }
    }
    // Add distance sensor view
    MapItemView{
        model: QGroundControl.multiVehicleManager.vehicles
        delegate: ProximityRadarMapView {
            vehicle:        object
            coordinate:     object.coordinate
            map:            _root
            z:              QGroundControl.zOrderVehicles
        }
    }

May I know where they are declared and how to know what they are?