AWK is a great language for both learning programming and processing text-based data files. Ninety-nine percent of the time, you will be working with text-based files, be it data tables, omic data, or whatever. Apart from being simple to learn and having a clear syntax, AWK provides you with the possibility to construct your own commands. Thus, the language may grow with you as you grow with the language. Hello World, again. This chapter closes with an example of how to measure sequence distances by dynamic programming. With the basic knowledge of AWK presented in this chapter, you are well prepared to master large-scale data processing and to learn any other programming language, if you feel to do so. All files from this chapter are available from the book’s GitHub repository at CompBiol3/13_AWK .