With Sony A7 IV, you can record your videos at a highest resolution of 3840 x 2160 at 60p, 50p,48p, 30p, 25p, 24p fps with bit rates up to 600 mbps and save in MPEG-4, XAVC S, XAVC HS, XAVC S-I, H.264 and H.265 formats. Sony A7 IV's 4K is the common standard resolution in consumer video world.
A great advantage of Sony A7 IV while shooting video at max resolution of 4K (UHD) is that there is no crop factor so you can use your lens with its actual focal length.
A7 IV features a high speed mode where it captures videos at 120fps which helps to create slow motion videos. If you shoot a video at a frame rate of 120fps and play it back at 24fps, the video will be 5x slower and longer than normal.
A7 IV has a built-in Stereo microphone and a Mono speaker. Sony A7 IV also has a port for an external microphone and a headphone port for connecting external headphones which make Sony A7 IV a very suitable camera high quality videography.
Sony A7 IV also features an Digital Video Stabilization mode where videos are stabilized in-camera while you are shooting. Keep in mind that this effect may crop your videos a little bit and doesn't help stabilizing still images. This kind of video stabilization effect can be replicated by using some of the advanced video editing softwares in your PC.