From Whonix wiki
Whonix is not amnesic
Unlike Tails, Whonix is not an Amnesic Live CD. If you install Whonix on your computer this will leave local traces on the harddrive, that you installed Whonix on that device. Any files you create will still exist after powering off or rebooting unless you securely wiped all signs of their previous existence.
There are no special measures to limit what is written to disk. This includes (non exhaustive list) user created files, backup files, temporary files, swap, chat history, browser history and so on. Whonix acts like an ordinary installed operating system. It can also not be prevented, that the host memory swaps to the host disk. There is a Recommendation to use multiple VM Snapshots and it is recommended to apply Full Disk Encryption on the host.
For more information on this topic, see also: Is there a substitute for Whonix's lack of an Amnesic feature / Live CD/DVD? Forensics?"
I translated amnesic in my native languages and still don't understand 100% what this means. I have only a vague understanding. With a search engine you don't find amnesic related to Computer science.