The ESP32-CAM Development Board is an electronic board based on an ESP32S SoC (System On Chip), equipped with a 2MPixel camera (OV2640) and a slot for a Micro SD memory card up to 4GB.
The board features a high-brightness LED that can be used as a flash or scene illuminator, as well as several GPIO lines for interfacing with the external world.
In this article by AdriRobot, you can find an excellent explanation of its operation and some examples to get started.