HSM can store a passkey that you optionally can use a touch + pin/password to unlock.

Passkey is a catchy but vague name for ssh keys used for website auth.

Everything else about them, such as HSM, is industry overlay motivated by their own motivations and aspirations.

A TPM is an HSM.

Nope, TPM secures your computer from you. HSM offloads sensitive tasks to a trusted device while letting you fiddle with the computer any way you want.

An HSM stores private keys securely. A TPM does this to implement secure boot and disk encryption. And for some reason a lot of people are afraid of disk encryption.

> And for some reason a lot of people are afraid of disk encryption.

I can answer that.

Disk encryption is a risk factor. If my desktop fails and it is unencrypted, I can take the disk and put it into another desktop and it will work.

With encryption, I am less sure. I do encrypt my desktop with LUKS but I vaguely remember that setting up an encrypted disk in Linux is tricky, there is a loop device involved for the decryption layer, some LVM config. And the kernel has to support all that, which it probably does, but again. It's been a long time since I tried.

So while my desktop and my laptops have encrypted partitions, the server running my archives and backup is not, because I value simplicity and access more than the extra security.

People using Windows or Apple hardware should be even more afraid of disk encryption, as they understand it way less than me.