What is metadata? Well, this is quite an embarrassing question! In an ambiguous way, metadata is data that describes data or information about information. In general, metadata is extra hidden information generated and embedded automatically in a digital file. The definition of metadata differs depending on the context in which it's used and the community that refers to it. It can be considered as machine-understandable information, or can be referred to as records that describe digital records. In fact, metadata can be subdivided into three important types: descriptive (including elements like author, title, abstract, and keywords), structural (describing how an object is constituted, and how elements are arranged), and administrative (including elements like date and time of creation, data type, and other technical details).
For example, camera settings (like camera marker, camera model, exposure time, ISO speed, focal length, shutter speed, and so on...