The BBC’s News web site has a video report on photo metadata. It’s a fairly good introduction to the topic, and worth five minutes of your time.
The reporter, Ian Hardy, makes the point that your grandfather’s photos often had some explanatory text written on the back of them – and that’s the metadata. In today’s digital world, the vast majority of images are being created with technical metadata (camera type, shutter speed, etc.) but often without any information on who is in the picture. The situation is not being helped by the new generation of social media web sites or mobile Apps for smartphones, Tablets or iPads that do not support management of metadata, or even worse, strip it out.
I’m a firm believer in the value of metadata. Unfortunately, at the moment, it’s a minefield, with competing and conflicting standards and poor, faulty, or non-existent support in applications and online services. Things can only get better, but there’s no guarantee that they will.