# Header

A name-value line of extra information on a request or response.

## What is **Header**?

A **header** is a name-value line of extra information on a request or response, such as `Content-Type`, `Authorization` or `Cache-Control`.

```text
Authorization: Bearer eyJhbGciOi...
Accept: application/json
```

Level: Apprentice · [More Web Development terms at this level](https://www.ask-codey.com/glossary/subjects/web-development/apprentice)

Updated: September 27, 2026

Source: https://www.ask-codey.com/glossary/header-web-development