Expandable memory, often known as secondary memory, refers to any memory that can be used to expand the memory of a device. Expandable or external memory refers to a microSD card that can be removed at any moment.
Xiaomi Mi A2 Lite Has Expandable Memory
Yes, there is a compartment available for the SD card, but you have to use one SIM card with an SD card cause there’s no system for using 2 SIM cards and an SD card at the same time.