A compiler-compiler is a type of computer program that can make new compilers. Compilers are programs that take a computer program written in a certain language and turn it into a form that computers can understand. A compiler-compiler can create programs that turn other programs written in a certain language into computer-understandable form. This means you don't have to write a compiler from scratch every time, like you would with a regular programming language. A compiler-compiler can make it easier for computer programmers to create programs for different languages.