# HTTP Header

HTTP headers are fields that can be transmitted as part of [HTTP](/glossary/h/http) request or response messages. They provide additional parameters or information for the transaction being performed.

An HTTP header consists of a field *name* for identification and a *value* containing the data.

More information is available at [https://www.iana.org](https://www.iana.org/assignments/message-headers/message-headers.xml)