What is the difference between the firmware and the operating system?

Question

In embedded devices such as printer, switches, I am confused what the difference between the firmware and the operating system is. Are embedded devices operating systems similar

Answer 1

Firmware is an application that occupies the WHOLE hardware resources. In the other words, there is no operation system able to dynamically loading an application on the system. The application is the operation system itself. The application manipulates ALL resources of the hardware. Thus, the application is extremely integrated with the hardware, it is almost unable to be cross-hardware. It is why the application is called firmware : a software is FIRMED to a specified hardware.

For example, the firmware on your air conditioner controls an specified compressor and an specified control panel. So, the firmware is going to be unworkable on the other air conditioner models.(Of course, the firmware is unworkable on the other appliances) The firmware is extremely hardware-depending.

Originally, firmware was defined as "Firmware is held in non-volatile memory devices such as ROM, EPROM, or flash memory". But the definition is obsolete: Your whole computer will be within firmwares only but without any software if you use solid-state disk(SSD) on that computer.

From my perspective, there is no firmware based on the embedded Linux, or you should call all softwares as firmwares while you use SSD.