html value attribute
snippet in html

default value input

user8585

<input type="text" id="fname" name="fname" value="John">

html lang attribute

user2776

The HTML lang attribute is used to identify the language of text content on the web. This information helps search engines return language specific results, and it is also used by screen readers that switch language profiles to provide the correct accent and pronunciation

Syntax
<element lang="language_code">
  
Example
Some French text in a paragraph:

<p lang="fr">Ceci est un paragraphe.</p>

html value attribute

user1511

<!-- The value attribute is used to for example fill data to an input -->

<input type="text" value="I was already filled" id="textInput">

<!-- The value can be set or copied using JavaScrpit -->
<script>
	// Get your element
	var input = document.getElementById('textInput');
	
	// get the value
	var value = input.value;
	
	// set the value
	input.value = "i was changed";
</script>