Someone mentioned this in one of the reviews of this product. The embedded (built-in) memory allows you to use the camera out of the box without needing to purchase additional media. You can use memory cards (that are the correct class) in this device. I purchased SanDisk 128GB memory card and it works great! However, you can only use/load one memory device at a time. Meaning you cannot partially record an event to the device memory and if the device memory fills have the device seamlessly switch to the memory card (or vice-versa). You would have to manually make the switch within the camera settings. It's not really an issue if you either have multiple cards, a card large enough to record a single event and/or you off load your recorded events to some other storage device (ie. your computer, data server, ect.).