System on Chip or SoC is the integration of essential components in a single chip that needs to run a computer system. SoC as its name suggests whole system on a chip, it includes CPU, GPU, IPU, Modems, etc depending on the purpose of the SoC.
From past few decades, technologies have evolved a lot and computers become more compact and smaller which can fit in a hand. Entry of apple in smartphone industries also makes a revolution on 2007 with first iphon, which had ARM core and GPU. As, mobile phone become smartphone, it become necessary pack a computer in a smartphone in such a way that, it has to be small, power efficient, light weight and which can perform basic tasks of a computer. So, its components should be arrange in such a way that everything can fit into hand. To do that, System on a Chip or SoC concept was introduced. Which can effectively eliminate all those limitations. But, this SoC concept was not new, infact Intel was the first to move the cache which use to be in the external chip that you plugged in on the CPU. But, this concept is widely used by chip manufacturer after smartphone industries grows.
One of the biggest myths in people about smartphone processor is smartphone don't have dedicated CPU or processor. Smartphone have SoC or System on a Chip. Qualcomm, Mediatek are the SoC manufacturer and Snapdragon 888, Snapdragon 720g, Snapdragon 765g, Mediatek Dimensity 1200, Dimensity 800, Dimensity 700u are the System on Chip (SoC). So, what you call smartphone processor is actually smartphone SoC.
For a smartphone SoC, it has CPU, which are basically designed by ARM, GPU, Modems or Signal Processing Unit (SPU) for connectivity and communication, Image Processing Unit (IPU), multimedia encoding decoding unit, navigation unit and other components depending on the chip manufacturer like Google is implementing AI in their own upcoming SoC for pixel devices.
Advantages
SoC are powerful as well as very much power efficient so, they produce less heat, cheaper and it can fit in a small space. So, it become easier to pack all other components in a smartphone. Due to less power consumption, it become possible to run a day without changing with a small battery, rather than a bulky heavy battery used in laptop or UPS. So, heat produced by the device is also become very less compared to computer or laptop. Otherwise, it come difficult to keep a smartphone in pocket for a long time. Due to SoC, it become possible to provide more faster performance and more optimization.
But, use of SoC is not limited in smartphone, they are widely used in smart devices and IoT devices like tablets smartwatchs, smart TVs, washing machine, domestic refrigerators, ACs smart LEDs and other IoT devices. Even in 2001 that ipod was based on ARM double core SoC.
Disadvantages
But, still we can't compare performance a SoC with a dedicated processor. A computer processor can easily outperform a high-end smartphone SoC. Both processor and SoC are designed for different purpose and different use. But, now SoC concept is also implimenting in computer processor. Processor manufacturer like Intel launched its integrated UHD and Iris Xe graphic which provides integrated GPU with their CPU which can run low to medium game. It is also cost effective. So, we can definitely expect in future SoC will be implemented in laptops.
Difference in Processor and SoC
The basic difference between Professor and SoC is processor have dedicated CPU or other processing unit which is used for a dedicated task in a computing system, whereas SoC is the combination of all other components along with CPU. It is designed to perform multiple tasks by a single chip.