It is a type of compact module used to integrate MicroSD memory cards, which are much more common today, into microcontroller projects. It works in exactly the same software logic (SPI protocol) as the standard SD card module. Thanks to the voltage regulator and logical level shifter integration on most models, it can be used safely with systems such as Arduino running 5V without damaging the card. Thanks to its small physical size, it has become the standard for data logging in weather stations, smart watches and portable IoT projects.
