Compiler is a computer program that translates code written in a high-level programming language (such as C++ or Java) into machine code that can be executed by a computer. By learning Compilers, you can gain a deeper understanding of how code is executed by a computer, which helps you write more efficient and effective programs. It also enables you to create new programming langauges or optimizing existing ones.
Studying Compilers usually requires the background of Data Structures and Algorithms and Computer Systems.