Android is a software system, system on a chip actually refers to the chip architecture.
Chip architecture refers to the description of the class and properties of the chip object. For each object class, the architecture defines the properties that the object class must have, it can also have additional properties, and the object can be its parent object. The mainstream chip architectures are ARM, MIPS, x86. Android is a soft system built on a chip, a hardware system.
Android is a free and open source operating system based on Linux, mainly used in mobile devices.
System on chip: The electronic logic gate circuit is burned to the silicon chip with a laser, thus forming a variety of chips.