Muddiest point - wk 3 readings..not meant for the laypeople

I would like to say that I really didn't get, as I may have stated several times in my reading notes, the jargon used in the article on LINUX.  I understand that it is written in C and that C is a programming language, like C++, etc.  What is the relationship between the OS and the hardware/software.  Is LINUX firmware, in that it is no hardware but also not software, either?  Is LINUX the vehicle that the software uses to deliver command info to the hardware?  Please, please would somebody explain this connection to me.  Translation is required.