what is html in jquery code example

Example 1: jquery set html of element

$("button").click(function(){
  $("p").html("Hello <b>world</b>!");
});

Example 2: jquery in html

<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>

Example 3: innerhtml jquery

var itemtoReplaceContentOf = $('#regTitle');
itemtoReplaceContentOf.html('');
newcontent.appendTo(itemtoReplaceContentOf);