What is the difference between MongoDB aggregation and query?

What is the difference between MongoDB aggregation and query?

MongoDB queries are used to retrieve documents from a collection, while aggregation is used to process data and return computed results.

Can you give me an example of a query?

Sure! A simple query could be: db.collection.find({ age: { $gt: 18 } }) to find all documents where age is greater than 18.

And how would an aggregation look?

An aggregation example would be: db.collection.aggregate([{ $group: { _id: '$age', count: { $sum: 1 } } }]) to count documents by age.

When should I use aggregation instead of a query?

Use aggregation when you need to perform calculations or transformations on your data, like grouping or summing.