What is the difference between SSD and HDD consoles?

The old Konlose only had one HDD inside and the Ps5 and Xbox Series X / S have built in an SSD what can the new consoles with SSDs do differently or better? Can you tell me a comparison that also exists in reality e.g. Horse-drawn carriage and car?

The main difference lies in the access time to files.
SSDs do not have a physical read / write head that has to move back and forth over magnetic disks.
This means that many small files can be transferred "faster", precisely because you don't have to wait for the head to move.

"Faster" means less "higher data rate" but "higher file rate". (Little difference.)

Theoretically, M.2 SSDs that are connected via PCIe can achieve significantly higher data rates - but if you don't move many and large files (at least 3-digit GByte range per file), you won't feel that in everyday life.

As with everything: Bechmark results often have nothing to do with practice. 😉