These little chips are like miniature SSD drives for your electronics. When you don't need something with as much storage as a micro SD card, but an EEPROM is too small, SPI (or QSPI) Flash chips give you on-the-order-of megabytes, with little cost and complexity. We use these chips all the time on our CircuitPython boards to let folks store code and assets like animations, fonts, images, configurations, audio clips, etc! A great way to add datalogging storage as well.