A C compiler is a special program that translates code written in the C programming language into machine code, which can be executed by a computer. This process allows developers to write human-readable code that can be converted into instructions the computer understands. There are various types of C compilers, including GCC (GNU Compiler Collection) and Clang. These compilers often come with additional tools for debugging and optimizing code, making it easier for programmers to develop efficient software. By converting high-level code into low-level machine code, compilers play a crucial role in software development.