How does SSHD work with logical drives?

Question

Hard disks

Good afternoon.
I wonder how hybrid drives work with logical drives. For example, do they cache something besides the data itself. Does it affect the speed in any way?
I would love to read in detail how SSHD works. how caching is implemented. Couldn't handle google. Basically holivar or superficially that they say so and so and that's it. Maybe someone can share useful links.