n.Information that appears at the top of each page of a document; a running head.ComputingStructured information that appears at the beginning of a data object and that provides information about the structure of data in the object body.ComputingInformation at the beginning of a packet that indicates the destination and is used to control how the packet is routed over the network.


A header1 may contain the title or author of the work and a page number. With the exception of the page number, information in the header is usually the same within a section of a document, or throughout the document; a work may use different headers on odd and even number pages. - A header2 is logically separate from the data it describes.