Aggregate function

Have you ever played with marbles? If you have a big bag of marbles, you might want to know some things about them, like how many marbles you have, or what's the biggest or smallest marble in the bag.

In the same way, when we work with a lot of data - like a list of names, ages, or prices - we might want to do some things with the data to help us understand it better. That's where "aggregate functions" come in.

Aggregate functions are like tools we can use to "aggregate" or group data in a certain way. Here are a few examples:

- COUNT: This tool helps us count how many entries we have in our data. It's like counting how many marbles are in the bag.
- SUM: This tool helps us add up all the values in a certain column of data. It's like adding up all the points from a game of marbles.
- AVERAGE: This tool helps us find the average, or mean, value in a certain column of data. It's like finding the average score of all the players in a game of marbles.

There are a few other aggregate functions too, but they all help us do something specific with our data. It's like using different tools in a toolbox to build something - each tool has a specific purpose and helps us get the job done.