With regard to electronic circuits, they can be widely divided into two categories.

Analog circuits:

They are also called linear circuits. Some of the most common analog devices on the market are radio receivers, transistor amplifiers, operational amplifiers, oscillator circuits, and so on. You can also get the circuits of maxim integrated products via https://www.elprotronic.com/collections/maxim-integrated for the automotive, industrial, communications.

All these circuits use some of the most basic electronic components such as transistors, diodes, resistors, capacitors, etc. The analog circuit uses a DC voltage range as its operating model.

There was a moment when all large electronic companies produced all their analog products of analog nature. But after the invention of digital circuits, the analog and numeric circuits have been mixed together to provide better performance and speed. 

Thus, the circuit that has both analog and numeric circuits produce mixed rather than analog or digital signals. There are many types of analog circuits that differ in size and performance. There are systems containing thousands of components with other systems that contain only one or two components.

Digital circuits:

Digital circuits use a number of discrete voltage levels in their operating model. It is considered a physical representation of Boolean algebra and the base of a digital computer.

In a digital circuit, there are especially two states, the high state, and the low state. The high state is labeled by the voltage level 1 and the bottom state is labeled by the voltage level 0.

Some of the most common systems using digital circuits are programmable logic computers (PLC), digital signal processors. , microprocessors, microcontrollers, integrated circuit micro controls (ASIC), network programmable doors in the field (FPGA), and so on.

Some of the most commonly used building blocks in a digital circuit are logical doors, adders, flip flops, counters, registers, multiplexers, and Schmitt triggers.