"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

--Sherlock Holmes - The Adventure of the Copper Beeches

Everything you do with a computer is managing data. Data comes in many different shapes and flavors. It's the music you listen, the movie you stream, the PDFs you open. Even the chapter you're reading at this very moment is just a file, which is data.

Data can be simple, an integer number to represent an age, or complex, like an order placed on a website. It can be about a single object or about a collection of them.

Data can even be about data, that is, metadata. Data that describes the design of other data structures or data that describes application data or its context.

In Python, objects are abstraction for data, and Python has an amazing variety of data structures that you can use to represent data, or combine them to create your own custom data. Before we delve into the specifics, I want you to be very clear about objects in Python, so let's talk a little bit more about them.