Metadata is described as the information about information. Metadata may describe a single item or a series of items. But metadata are essentially a set of data that tells something about an item or a file.
In the case of photos, for example, the metadata could contain the date when an image was taken. It would contain the brand and the model of the camera which was used to take the photo. Exposure information are also written. The aperture, the shutter speed and ISO used can easily be known through the EXIF metadata. In addition to this data, the file size and the file type of the photo is also indicated here. The photos metadata also contains information about the focal point used and whether the flash was fired or not. And when the image is edited, the date and time of edit is also recorded.
There is also another way in which metadata are created. This time it’s more of a creation of the person using the photo. Usually when people upload photos to various sites on the internet they are asked to provide keywords or tags to describe the photo. This is how metadata is created anew or more information is added to it. The better description the photo has the better chances that it will appear searches. If one is trying to showcase his work, he should provide quite descriptive and popular keywords for his photos. That is because the sites rely on the tags to come up with results for the searches done by its users.