C language:

Powerful and continuous, C language is compact and simpler, and it is good for writing system-level programs, such as operating systems. C was the first programming language to make system-level code migration possible.

C language is good for writing small, fast programs. Easy to combine with assembly language. It is highly standardized, so versions on other platforms are very similar. But support for object-oriented technology is not easy. Grammar can be very difficult to understand and can be abusive.

The core of C language is portable, but limited to process control, memory management, and simple file processing. Everything else is about platforms.