The UNIX operating system was the first major program writer in C language. C compilers are compatible with most of the available operating systems and computer architectures. The compiler turns the instruction writer in a C program into an executable form your computer can work with.
C is the best language discovered to date and it works comparatively closer to the hardware. Learning C language will help you understand the basics of different languages. Most of the languages have derived elements from C including PHP, Java, Pearl, Python, Rust, D, and Unix C shell. You can learn how things work at the system level and understand computers at a profound level.
You may spend few bucks and buy a book written by experts in c language, however this article focuses on free tutorials and resources you can use to learn C programming.