Lesson 2 of 5 · about 20 minutes

Files and folders

🏠The everyday picture

In an office almirah, papers go into files, files go onto labelled shelves, and the shelves sit in one cupboard. You can find any paper if you know the path: "cupboard 2, accounts shelf, 2026 file". A computer stores your work the same way.

📘What it really is

A file is one piece of saved work: a photo, a letter, a song, a spreadsheet.
A folder holds files, and can hold other folders inside it.
The path is the route to a file, for example Documents › Shop › stock-sheet.xlsx. On Windows it's written C:\Users\Asha\Documents\Shop\stock-sheet.xlsx; on a Mac, /Users/asha/Documents/Shop/stock-sheet.xlsx; on Linux, /home/asha/Documents/Shop/stock-sheet.xlsx.
A file's name ends in a dot and a file type, such as .jpg (photo), .pdf (document to read), .xlsx (spreadsheet) or .exe (a Windows program).

Where things go by themselves:

Things you download from the internet usually land in the Downloads folder.
Photos from a phone camera go to the Gallery or Photos app, and, on Android, are stored in a folder called DCIM.

📝A worked example

Asha keeps the shop's papers in a clear set of folders:

Documents
└── Shop
    ├── Stock
    │   ├── stock-sheet-2026-10.xlsx
    │   └── stock-sheet-2026-11.xlsx
    ├── Letters
    │   └── supplier-order-2026-11-07.pdf
    └── Bills

Her file names follow one pattern: what it is, then the date as year-month-day. Sorted by name, the files then also come out in date order.

🖱️Try it

Make a folder called Practice in your Documents folder (right-click, then New, then Folder; on a Mac, File, then New Folder).
Inside it, make two folders: Photos and Letters.
Move one file from Downloads into Letters by dragging it.
Windows: in File Explorer, click View, then Show, then File name extensions (Windows 10: the View tab, then tick File name extensions), so you can see the endings such as .pdf and .jpg. Windows hides them unless you turn this on.

⚠️Common mistakes

Saving everything to the Desktop or Downloads, until nothing can be found.
Names like final, final2 and final-REAL. Use a date instead: report-2026-11-07.
A file called bill.pdf.exe. With endings hidden, it looks like bill.pdf, but it's a program, and opening it can install harmful software. Showing file name extensions helps you spot it.

✅Quick check

Why put the date as 2026-11-07 rather than 07-11-2026 in a file name?

Show the answer

Because year-month-day sorts in date order when the computer sorts by name. Day-first dates mix the months and years up.

You downloaded a form, but can't find it. Where do you look first?