There are two kinds of VMM(Virtual Machine Monitor) accord to their virtualization level, system VM and process VM.
I know that KVM is a "system VM", and what about QEMU?
Is it same as KVM?
KVM is built on to of QEMU and QEMU is a system VM as you are calling it.
I do not know your source of information, but from https://en.wikipedia.org/wiki/Virtual_machine
A system virtual machine provides a complete system platform which supports the execution of a complete operating system (OS).
Full system emulation. In this mode, QEMU emulates a full system (for example a PC), including one or several processors and various peripherals. It can be used to launch different Operating Systems without rebooting the PC or to debug system code.