This chapter introduces the C programming language's overall features, why we should use this language, the characteristics of this language, and a short description of its history. The author also explains the structure of a C program and how to execute it in different environments. Executing a C program includes several steps such as editing, compiling, and linking. For each of these tasks, dedicated software is available. A user requires an editor to write code in it. Editors such as Notepad, Visual Studio Code, vi/vim editor are commonly used for this purpose. Several C programming language standards exist for program execution, and C99 and C11 are popular among them. This chapter also contains the procedure for executing code in Windows, Linux, and Mac systems.