The most fundamental difference between external HDDs and external SSDs lies in their internal data storage methods, which determine almost all their characteristics. We can understand this with a simple analogy: an external HDD is like an old-fashioned vinyl record player, while an external SSD is like a large, high-speed USB flash drive.

NAND flash is an electronic medium used to store data, and its core feature is non-volatility. This means that even when power is completely lost, the data can still be preserved for a long time. This is very different from the computer’s RAM, which clears all data once power is cut.

Phison Electronics’ CEO recently warned in an interview with foreign media that NAND flash memory may face a long-term shortage over the next decade. This is not merely a short-term price fluctuation — it may signal a structural imbalance in the entire semiconductor storage ecosystem.