It used to be that different kinds of information were stored on very different media: paper for text, canvas for paintings, film strips for photographs and video, tape and vinyl records for audio, floppy disks for computer files, and so on. That’s where the icons come from.
On the other hand, now that high-capacity hard disks and flash memory exist, many different kinds of information can be and often are stored on the same device. You can’t easily tell what kind of information is stored on it just by looking at it; you have to actually read it.
That raises a mildly interesting point.
It used to be that different kinds of information were stored on very different media: paper for text, canvas for paintings, film strips for photographs and video, tape and vinyl records for audio, floppy disks for computer files, and so on. That’s where the icons come from.
On the other hand, now that high-capacity hard disks and flash memory exist, many different kinds of information can be and often are stored on the same device. You can’t easily tell what kind of information is stored on it just by looking at it; you have to actually read it.