HTML Forms :

An HTML form is used to collect user input.It contain normal
context, markup, special elemets called controls.Users can
modify its control by entering text, Selecting menu items etc.
It also consist of labels, radio button and push button such 
as submit and reset button.

Code :

<form action="url">
<p>
<label for="FirstName">First Name:</label>
<input type="text" id="FirstName"><br>
<label for="LastName">Last Name:</label>
<input type="text" id="LastName"><br>
<input type="radio" name="sex" value="Male">Male<br>
<input type="radio" name="sex" value="Female">Female<br>
<input type="submit" value="send">
</p>
</form>

HTML Header :

HTML Header is an element which is used to represent intro-
ductory element and navigational aids.Its also contain logo,
search form, name and other elements.

Code :

 <header>
 <h1> heading </h1>
 <p> infromation </p>
 <p> additional informatin </p>
 </header>