GridFS (https://docs.mongodb.com/manual/core/gridfs/#gridfs) is a technology included with MongoDB that allows you to store files directly in the database. GridFS is a virtual filesystem mainly designed to handle files larger than 16 MB in size. Each document is broken down into chunks of 255 KB except for the last chunk, which could be less than 255 KB. By default, two collections assigned to an arbitrary bucket are used. The chunks collection stores the actual contents of the file. The files collection stores file metadata. Within your database, you can designate as many buckets as needed.
Let's start by discussing why you might want to incorporate GridFS into your applications.