No, a "system on a chip" means the chip includes things that are not typically part of the CPU but were always parts of computer systems: busses, I/O, sometimes memory, auxillary HW functions like audio, image/video processing or codecs.
Nowadays CPU's often have a bunch of these things anyways and you'll hear that all CPU's sort of resemble SoCs. They also tend to have auxillary, lower-power processors that manage power and other things for the main processor.
