Check out example codes for "html template". It will help you in understanding the concepts better.

Code Example 1

<!DOCTYPE>
<html>
  <head>
    <title>Title</title>
    
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="style.css">
  </head>
  
  <body>
    
  </body>
</html>

Code Example 2

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>Page Title Goes Here</title>
  <meta name="description" content="Description Goes Here">
  <link rel="stylesheet" href="style.css">
</head>
<body>
  // if scripts is required add:
  <script src="js/scripts.js"></script>
</body>
</html>

Code Example 3

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>My Page Title</title>
  <meta name="description" content="My Page Description">
  <link rel="stylesheet" href="css/styles.css?v=1.0">
</head>
<body>
  <script src="js/scripts.js"></script>
</body>
</html>

Code Example 4

<!DOCTYPE html>
<html>
<body>

<h1>My First Heading</h1>
<p>My first paragraph.</p>

</body>
</html>

Code Example 5

<!doctype html>
<!--[if IE 8]><html lang="pt-br" class="no-js ie8 oldie"><![endif]-->
<!--[if IE 9]><html lang="pt-br" class="no-js ie9"><![endif]-->
<!--[if gt IE 9]><!-->
<html lang="pt-br" class="no-js">
<!--<![endif]-->
<head>
	<base href="">
	<meta charset="utf-8"/>
	<meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0"/>
	<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent"/>
	<meta name="apple-mobile-web-app-capable" content="yes"/>
	<meta name="theme-color" content="#111111" />
	<meta name="description" content=""/>
	<title></title>
	<link rel="author" href="humans.txt">
	<link rel="manifest" href="manifest.json" />
	<link rel="apple-touch-icon" sizes="114x114" href="apple-touch-icon-114x114-precomposed.png">
	<link rel="apple-touch-icon" sizes="72x72" href="apple-touch-icon-72x72-precomposed.png">
	<link rel="apple-touch-icon" sizes="57x57" href="apple-touch-icon-57x57-precomposed.png">
	<link rel="apple-touch-icon" sizes="57x57" href="apple-touch-icon.png">
	<link rel="shortcut icon" sizes="16x16" href="favicon.ico">
	<link rel="stylesheet" media="all" href="styles/index.css">
</head>
<body>
	<!-- fallback -->
	<noscript>You need to enable JavaScript to run this app.</noscript>
	
	<!-- app -->
	<main id="root" role="main"></main>
	
	<!-- libraries - scripts at the bottom for fast page loading -->
	<script src="scripts/index.js"></script>
</body>
</html>

Code Example 6

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
</html>

Learn ReactJs, React Native from akashmittal.com