3 Credit Hours. Most importantly, it allows you to make use of the facilities provided by the system.
Every computer has an operating system.
UNIX is a multiuser Operating system that have been developed over the years by universities, industry, researchers. It is considered the most developed operating system. C is flexible and powerful, it was built by software engineers to be used by software engineers, it is simply a way to create efficient programs. It is general purpose and very flexible tool. At the low end, C is as close to a symbolic representation of processor operation as a high-level programming language can get.