What do you mean by metadata?

Meta data can be described as the Data that gives information about what the primary data is about (e.g., if a photo is the primary data, its metadata might consist of what its resolution is, when the photo was taken, meta data gives additional information about the original subject.

Metadata is data that describes other data. Meta is a prefix that in most information technology usages means “an underlying definition or description.”

Metadata summarises basic information about data, which can make finding and working with particular instances of data easier. For example, author, date created and date modified and file size are examples of very basic document metadata.Having the ability to filter through that metadata makes it much easier for someone to locate a specific document.