Metadata is data that describes other data. Metadata is not visible on the surface of interfaces, whether it's a website, photography, or something else. Metadata is content hidden behind visible content. Metadata is, however, parsable, which means that machines, such as search engines, can read it.
On a website the most common type of metadata is:
- Date created
- Date modified
Metadata is used by search engines to learn about the content and structure of your website, which directly influences your SEO (Search Engine Optimization).
On a photo common metadata is:
- File extension/format
- Camera brand
- Capture time
So metadata is a kind of hidden watermark on a photo that can’t be seen on the outside, but if you open any photo in an app like Photoshop, you can access all this information (unless it has been purposely removed).
If you have a huge database, metadata makes it much easier to search for specific files. Each metadata item can be used as a filter so you can narrow down your search results effectively and find what you’re looking for, e.g. based on date, author, brand, or size.