Expandable Memory refers to a type of computer storage that can be increased in size by adding more components or modules. This is different from fixed, non-expandable memory which has a predetermined and unchangeable amount of space. Expandable memory is often used for devices such as smartphones, tablets, and laptops to provide additional storage capacity beyond the built-in memory. It can be in the form of microSD cards or other similar expansion slots that allow users to easily increase their device's storage without having to purchase a whole new device.