A compiler error is an error that the C programming language (or any other programming language that uses a compiler program to generate an executable file) produces whenever its program detects an error during program compilation time. These types of error are triggered whenever a set of requirements or program rules imposed by the C programming language are not met.
The cause of compilation errors can generally be classified as Syntax errors or Semantic errors.
Syntax errors are errors generated during compilation whenever a syntax rule used by the C programming language is not met, while Semantic errors are errors produced during compilation whenever a code in the program is not meaningful to the compiler.