I read, that drivers are a way to expand the Kernels abilities to communicate with hardware devices, since there are so many and will be even more the Kernel has to be expandable. In order to establish a communication to a hardware device via the driver a Program in Userspace has to establish a connection to the driver by the systemcall ioctl().
Now, a PTTY (pseudo Termimanl) simulates sth. that was originally real hardware, and there is even a driver that has to be accessed with ioctl() in order for a program to communicate with a PTTY.
Because of its special status, I am unsure how this pseudo Terminal is finally realized, is it a part of the Kernel or the Userspace ?
(P.S. is a PTTY the same as TTY )