A filename is the name given to a computer file so you can identify it, organize it, and open it when needed. Just like you label your school folders “Math Homework” or “Science Project,” files on a computer need names so you and the computer can find them again.

A filename usually has two parts separated by a period: the name you choose and the file extension that tells the computer what type of file it is. For example, “MyStory.docx” shows it's a document, while “SummerVacation.jpg” indicates it's a photograph. The extension helps your computer know which program to use when opening the file.

Good filenames are specific and descriptive. Instead of naming something “Document1,” you might call it “BookReport_TomSawyer” so you'll know exactly what it is six months later. Some people add dates to their filenames, like “ScienceNotes_2024-03-15,” to keep track of different versions.

Filenames have rules: they can't include certain symbols, like slashes or colons, that computers use for other purposes. If you try using these, your computer will politely refuse or suggest alternatives. When you save something for the first time, choosing a clear, organized filename is like giving your future self a helpful gift that makes the file easy to locate among the hundreds or thousands of other files on your computer.