Filename extension

A filename extension is like the last name of a file that helps the computer understand what kind of file it is. For example, if we have a picture we want to save, the computer needs to know that it's a picture so it can use the right program to open it.

Think of it like your last name - if your last name is "Smith", it tells people something about you, like where you come from or who your family is. The extension of a file works the same way - it tells the computer what kind of file it is and how it should be opened.

Some common extensions you might see are ".jpg" for pictures, ".docx" for Microsoft Word documents, and ".mp3" for music files. They all tell the computer what program to open so you can see or hear what's inside the file.

So, just like how your last name tells people a little bit about you, a filename extension tells the computer a little bit about the file it's attached to!