Chapter 9 covered one popular NoSQL database structure (key/value pairs via Redis), and this chapter covers another: document-centric data stores via MongoDB.
MongoDB isn’t the only document-centric database. Other popular versions of this type of data store are CouchDB by Apache, SimpleDB by Amazon, RavenDB, and even the venerable Lotus Notes. There is some Node support of varying degrees for most modern document data stores, but MongoDB and CouchDB have the most. I decided to cover MongoDB rather CouchDB for the same reasons I picked Express over other frameworks: I feel it’s easier for a person with no exposure to the secondary technology (in this case, the data store) to be able to grasp the Node examples without having to focus overmuch on the non-Node technology. With MongoDB, we can query the data directly, whereas with CouchDB, we work with the concept of views. This higher level of abstraction does require more up-front time. In my opinion, you can hit the ground running faster with MongoDB than CouchDB.
There are several modules ...