Corpus linguistics is a rapidly growing discipline in linguistics, which broadens our understanding of human language by focusing on actual use of language in different contexts. Understanding Corpus Linguistics is an introduction to the goals, methods, and achievements of corpus linguistics, which is written mainly as a textbook for undergraduate and graduate students, while advanced scholars also could benefit from reading it. The authors, who have been engaged in corpus linguistics as their main interest, try to show what corpus linguistics is and how it helps us to better understand language.