To summarize, MongoDB is a document-based NoSQL database that offers advantages in data management such as document-oriented data storage, flexible document schemas, and powerful analytics. To use MongoDB in a Laravel Lumen application, developers need to install the MongoDB package, create a new cluster, link it to the application, and configure the database settings. A model is created to interact with the MongoDB database, and a controller is created to fetch, update, create, and delete data from the collection. The application can be tested by making an API request to the "all" route, which returns all the blog items in JSON format.