How does computer understand whether some file is text, video, image. As it only understands binary at the end of the day ?

Question

I tried going through various articles and videos available online, but couldn’t really understand, properly!!

In: 0

Answer 1

Some files have a header that “explains” what the format is. There is also a convention – the file extension is a strong hint about the file type – your computer maintains a set of “file associations”, or correspondence between the extension and the file type, to help with this. But mostly…they don’t. If there is no header, and there is either no extension or no mapping for the extension, or if somebody has renamed the file with a different extension that no longer matches its true format….you have to tell it. That’s what happens when you get that “what program would you like to use to open this” message.