MongoDB has a lot of things going on under the covers, most of which we may either take for granted or sometimes do not need to know to work with MongoDB. The team behind MongoDB has been working hard to make MongoDB faster, easier, and more humongous. If we understand how things work and what impact it's going to have on our data or performance, it would help us build better applications by making the most of all that is offered by MongoDB. MongoDB does not support joins and transactions. There are alternatives to this but if you require ACID transactions, you should use an SQL database.

In the subsequent chapters, we shall learn a lot about using MongoDB but we may not see many MongoDB internals. I do hope that this chapter makes the underlying concepts easy to understand.