Although MongoDB and MySQL both are free and open source databases, there is a lot of difference between them in the terms of data representation, relationship, transaction, querying data, schema design and definition, performance speed, normalization and many more. To compare MySQL with MongoDB is like a comparison between Relational and Non-relational databases.
Both Monk and Mongoose are distinctive, despite the fact that they are two ways to deal with the same fundamental issue. Mongoose is a very advanced all out ORM. More components, yet more many-sided quality. Monk is smaller in scope and thus easier to understand
The better thing is begin coding with the essential mongodb driver module straightforwardly. When you see how that functions, and how parts of it are irritating, you will comprehend the advantage of Monk and can give that a shot to check whether you like it. I wouldn’t prescribe mongoose to a beginner. Mongodb is as of now sufficiently dubious to learn keeping in mind mongoose can be useful, it’s API is entirely otherworldly and accept you definitely know the precarious parts of mongodb.