A tag is nothing more than a keyword that describes the image to which it is attached. And the premise behind tagging is a simple one: The more tags you assign to an image, the better the chances are of finding it. It turns out that there are a number of standards out there that attempt to regulate many of the different characteristics associated to digital images.

Some of the standards apply to compression. For example, the JPEG standard allows for the reduction of digital information that represents the image we see. By eliminating a certain amount of redundancy that's inherent in a raw digital image, the physical size of that file will be substantially smaller.

Read more: Service tags digital photos for you

Ce mystère n'en serait pas un en fait, le blog anglophone de Techcrunch a eu l'information que ce sont des personnes qui sont payés pour tagguer les photos selon un salaire de 4 cents par 5 photos. Pour quelqu'un de très productif, cela peut représenter un salaire de 1,20$ par heure.