The Lumix GH5 features in-body image stabilization, which means that the camera shifts the image sensor to compensate for movement, camera shake and so on. A big benefit of the Micro Four Thirds sensor is that,  because it's so much smaller, the camera is able to provide stabilization that's far more effective than APS-C or full-frame bodies. Mount any lens and you will benefit from 5 stops of stabilization, but compatible Dual IS lenses from Panasonic will deliver a huge 6.5 stops for gimbal-free shooting!