Database systems need query languages in order for humans and software applications to interact with them in an efficient way. There are a number of graph query languages out there already (Gremlin and SparQL, to name just two), and some of these have certainly inspired the creation of Cypher, but Cypher is quite different than anything else you may have come across before. No book on Neo4j would be complete without at least spending some time on it—in spite of the fact that there are entire books, presentations, and courses available for you to review.