What is a chip? How to classify

First distinguish several basic concepts: what are chips, semiconductors, and integrated circuits?
Semiconductor: materials with conductivity between conductor and insulator at room temperature. Common semiconductor materials include silicon, germanium, gallium arsenide, etc. Now silicon is the commonly used semiconductor material for chips.
Integrated circuit: A miniature electronic device or component. Using a certain process, the transistors, resistors, capacitors, inductors and other components required in a circuit and their wiring are interconnected together, made on a small piece or several small pieces of semiconductor chips or dielectric substrates, and then packaged in a tube shell to become a micro structure with the required circuit functions.
Chip: The transistor and other devices needed for a circuit are made on a semiconductor (from Jeff Damer). The chip belongs to the carrier of integrated circuit.
Strictly speaking, integrated circuits ≠ chips.
But in a narrow sense, there is no difference between the ICs, chips and integrated circuits that we refer to everyday. The IC industry and chip industry that we usually discuss refer to the same industry.

To sum up in one sentence, a chip is a physical product made of semiconductor as raw material after the integrated circuit is designed, manufactured, sealed and tested.

Slice classification
With so many chips, is there any systematic classification method? In fact, there are many ways to classify chips:
It can be divided into analog chip and digital chip according to signal processing mode
Signals are divided into analog signals and digital signals. Digital chips are used to process digital signals, such as CPU, logic circuits, etc; Analog chips process analog signals, such as operational amplifiers, linear regulators, reference voltage sources, etc.
Nowadays, most chips have both digital and analog features. There is no absolute standard for what kind of product a chip belongs to. It is usually differentiated according to the core functions of the chip.
According to the application scenario, it can be divided into: aerospace chip, vehicle specification chip, industrial chip and commercial chip
Chips can be used in different fields such as aerospace, automobile, industry and consumption. The reason for this is that these fields have different performance requirements for chips, such as temperature range, accuracy, continuous trouble free operation time (life), etc. for instance:
The temperature range of industrial grade chips is wider than that of commercial grade chips, and the performance of aerospace grade chips is the best, while the price is the most expensive.
It can be divided into GPU, CPU, FPGA, DSP, ASIC, SoC
The touch chip, memory chip and Bluetooth chip just mentioned are classified according to their functions. Also, enterprises often say that "our main business is CPU chips/WIFI chips", which is also divided from the perspective of functions