Dual card slots are a feature found on some cameras, including the Sony A7rii. This means that the camera can support two separate cards, which can be used to store different types of photos and videos. The dual card slots on the Sony A7rii make it possible to use two different types of cards, such as a memory card that stores photos and a card that stores videos. This is an important feature because it allows you to save your photos and videos in different ways.
Additionally, the dual card slots on the Sony A7rii make it possible to use two different types of cameras at the same time. This is helpful if you want to take pictures and videos of the same thing, but use different cameras to do so.