Metadata is like extra information about something. A tag is a kind of metadata, and it's like a name or label that helps you remember what something is. For example, if you have a photo of your cat, you might give it the tag 'cat'. Now, whenever you look for photos of cats, that tag will help you find the one you want. Tags can also be used for other things, like websites, songs, articles, and more. They can help you quickly find what you are looking for.