What is compiler construction in computer science

The study of compiler construction is both an introduction to techniques for the translation and improvement of programs, and a practical exercise in software engineering.
Keith D.
Cooper, Linda Torczon, in Engineering a Compiler (Second Edition), 2012 Compiler construction is a complex task.

A language rewriter is usually a program that translates the form of expressions without a change of language.
A compiler-compiler is a compiler that produces a compiler (or part of one), often in a generic and reusable way so as to be able to produce many differing compilers.

Compiler construction is a complex task.
A good compiler combines ideas from formal language theory, from the study of algorithms, from artificial intelligence, from systems design, from computer architecture, and from the theory of programming languages and applies them to the problem of translating a program.