Differences between scripting for the mongo shell and using it directly

When writing scripts for the mongo shell we cannot use the shell helpers. MongoDB's commands like use <database_name>, show collections, and other helpers are built into the shell and so are not available from the JavaScript context where our scripts will get executed. Fortunately, there are equivalents to them that are available from the JavaScript execution context, as shown in the following table:

In the previous table, it is the iteration cursor that the mongo shell returns when we query and get back too many results to show in one batch.

Using the mongo shell, we can script almost anything that we would from a client, meaning that we have a really powerful tool for prototyping and getting quick insights into our data.