What is the meaning of Header?

The upper portion of a page (or other) layout.

Text, or other visual information, used to mark off a quantity of text, often titling or summarizing it.

Text, or other visual information, that goes at the top of a column of information in a table.

A font, text style, or typesetting used for any of the above.

The first part of a file or record that describes its contents.

Clipping of header file.

the first part of a packet or stream, often containing its address and descriptors.

A brick that is laid sideways (on its largest face), for example at the top of a wall or within the brickwork, with its smallest side showing (oriented so that that side is wider than it is tall).

A horizontal structural or finish piece over an opening.

A machine that separates and gathers the heads of grain etc.

The act of hitting the ball with the head.

Someone who heads the ball.

A headlong fall, jump or dive.

A raised tank that supplies water at constant pressure, especially to a central heating and hot water system.

A pipe which connects several smaller pipes.

The rodeo performer who drives the steer toward the heeler to be tied.

One who puts a head on something.

To strike (a ball) with one's head.

Source: wiktionary.org