Close to the computer
C is used in operating systems, device software, and other programs that work closely with hardware. A developer can use it to decide how memory is allocated and released. That control can be useful, but mistakes can cause crashes or security problems.
C code is usually compiled into a program for a particular kind of computer. C++ and Objective-C grew from C. C# has a similar-looking name and some familiar syntax, but it is a separate language with a different way of running programs.