Welcome to today's lesson! Our topic for the day is data aggregation, a crucial aspect of data analysis. Like summarizing a massive book into key points, data aggregation summarizes large amounts of data into important highlights.

By the end of this lesson, you'll be equipped with several aggregation methods to summarize data streams in JavaScript. Let's get started!

Let's say we have an array of numbers denoting the ages of a group of people:

Common questions we might ask are: How many people are in the group? What's their total age? Who's the youngest and the oldest? JavaScript's handy built-in properties and functions like length, reduce, Math.min, and Math.max have our answers:

These functions provide essential aggregation operations and are widely used with data streams.