What is Embedded Firmware Development?

To understand the answer to this question, it helps to have an understanding of the distinction between firmware and software. Both are expressed in terms of data being read and manipulated by a central processor, but the primary distinction is often found in how easily firmware and software can be changed.

Software is "soft" as it lives in RAM in a system. In other words, the program and data it requires is lost when power is cut from the system. The instructions that make up a program and the data used by the program are loaded from permanent memory when you need them. Essentially, this means software can be easily changed as needed. Simply change the data stored in memory, and you’ve just changed the instructions used in your program.

Firmware is said to be "firm" in that it is difficult to change once it is programmed and loaded onto a hardware platform. Similar to software, the instructions that make up firmware are stored on a physical device, but the instructions are intended to be unchangeable once written. Any computing system will use firmware to define the low-level functions of a system, which may include loading an operating system and software into memory. The relationship between the two is shown below.