Since the early 1980s, when C was the dominant language in the UNIX world of minicomputers, it has been extended to personal computers and mainframes, and most software developers have chosen C to develop their subprocessors, spreadsheet software, compilers, and so on. Because they know that C can produce compact and efficient programs. More importantly, they know that these programs are easy to modify and easy to adapt to new computer models.
What is helpful for companies and people familiar with the C language is equally helpful for other users. More and more computer users have turned to C to take advantage of its benefits. You don't have to be a computer professional to use C.
And by the 1990s, many software developers were turning to C++ for big programming projects. C++ grafted object-oriented programming tools on to C (object-oriented programming is a philosophy that tries to let the language adapt to the problem, rather than letting the problem adapt to the language). C++ is pretty much a superset of C, meaning that any C program is simultaneously, or pretty much, a valid C++ program. By learning C, you will be able to pick up much of what C++ has to offer more easily.
Regardless of the popularity of newer languages like C++ and Java, C is still an important skill in the software industry, and it is generally listed in the top 10 of the most desired skills. In particular, C also makes up for or is missing in programming embedded systems. That is, it will be used to program the microprocessors that are becoming popular in cars, cameras, DVD players and other modern devices. Likewise, C has begun to enter the realm of scientific programming that has long belonged to FORTRAN. Finally, because it is a suitable language for developing operating systems, C also plays an important role in the development of Linux. Even now, C will remain strong.
In short, C is one of the most important programming languages and will continue to be so, and if you want a job in programming, one of the first things you can't afford to be without is the ability to use C.