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Files

Before we talk more about the tools we recommend, we need to talk about how a computer stores information. These days you don't have to think about it too much as it is hidden away from you by your phone or computer, but having a basic understanding of this is essential. How does your computer store the programs that you have installed, the photos you have taken, or the online worlds you have explored in games? How does it find that information again when you need it?

In order to find information, computers store it into something called a file system. They contain two different kinds of objects: files and folders (also called directories). A file is something that stores information, and a folder is a way of grouping together multiple files. Folders can also contain other folders. Every file and folder has a name that can be specified by the user. This is very abstract at the moment, so we will give some concrete examples.

Example 1: Storing and organizing photos

If you have a large number of photos, you probably want to organize them in some way. This could be both a physical photo album or a digital one (like DFoto). Every photo is a file, which contains the information to actually display the photo. You might also name photos with the date they were taken.

If you were at some event, and took a lot of photos there, you could collect all of those photos into an album and give it a label with the name of the event. This is similar to a folder/directory. If you then go to multiple events in a year, you could group all event albums into an album for the entire year. This would then be a folder containing folders, which then contain files.

Example 2: Storing books in a library

Libraries have a lot of books and need some way to store them where you can still find them efficiently. Books are grouped together into shelves based on the topics they cover and the shelves are given names. Your book on JavaScript will probably be on the shelf about programming. But as there are a lot of different subjects, we group together shelves that cover similar topics. It doesn't make sense to have your books on programming right next to children's books, or if it would be next to fiction. Here the books would be your files, the shelves and sections would be folders.

Going back to computers, we don't just have one type of file like in the above examples, we have multiple! Some files are programs that you can run, others are photos that you can open in some program to look at. Some are videos that you can watch, other are PDFs that you can read. Some files contain code that you write that will then be run by the computer. How a computer interprets a file depends on its contents.

How do we then refer to a specific file? With something called a path! We will cover paths more in depth later, but the basic idea is that we list all directories you have to look in to get to the file, and then the name of the file itself. In order to make it clear where the name of one directory ends and a new one starts, we separate them with forward slashes (/).

{{ .windows }} Windows usually uses backward slashes (\) in paths instead. We will go through the differences between so called "Unix" systems and Windows later!

A concrete example would be how you find the text for this chapter! The project is on GitHub. All files for this book are in a folder named src. Inside of it, there is one folder for each of the sections you see to the left. This document is in the folder called beginner. The file itself is called files.md. The path to it would thus be src/beginner/files.md.