Header image
A header image is a large image or graphic displayed at the top of a webpage, usually just below the navigation bar. It’s often the first thing visitors see and can set the tone for the entire set. Header images are used to grab attention, showcase a product or service, or highlight a brand. A well-chosen header image works to engage users right away.
See also: Above the fold, Image optimisation, User interfaces
Further reading: Types of Photos You Need on Your Website