SO-DIMM stands for Small Outline Dual In-line Memory Module. It is a type of computer memory designed for laptops and small form factor devices. SO-DIMMs are smaller than standard DIMMs, making them ideal for compact spaces while still providing the necessary memory performance. These memory modules come in various capacities and speeds, allowing users to upgrade their devices easily. SO-DIMMs are commonly used in laptops, mini PCs, and networking equipment, providing efficient memory solutions without taking up much space.