Describe the usage of <footer>, <article>, <section>, and <header> HTML5 semantic elements.
<footer>: This semantic element is used to contain information that should appear at the very end of the content section. It also contains additional information of the section such as copyright information, Author's name, and related links.
<article>: This one contains a self-contained composition which can logically be recreated by developers outside of the page without losing its primary meaning. For example news stories and blog posts.
<section> : This HTML5 semantic element holds content that shares a common informational purpose or theme.
<header>: Developers use this to contain navigational and introductory information about a section of the page, such as section heading, publication date and time, author’s name, content table, etc.