A form is an area that can contain form elements.Form elements are elements that allow the user to enter information (like text fields, textarea fields, drop-down menus, radio buttons, checkboxes, etc.) in a form.

forms are used in surveys, on-line order forms, feedback, and send e-mail in  general forms are used to inquire inputs from users. 

A form is defined with the <form></form> tag.s

</FORM>

Name is a name given to the form describing its purpose

Action = "url" the url of where the data will be submitted

Method

o        GET -- this is the default method and causes the fill-out form contents to be appended to the URL as if they were a normal query.

o        POST -- this method causes the fill-out form contents to be sent to the server in a data body rather than as part of the URL.

Form elements

Inside a form are the form's elements like text, input, select, textarea, button, radio buttons and check boxes. Note that you can't insert another form in a form. The INPUT tag is used to add an input element inside a form

<input type="text" name="UserName" value="">

<input type="password" name="UserPassword" value="">

<input type="submit" name="SendData" value="Send">

Not that the value attribute is the button's caption.

<input type="Reset" name="ResetForm" value="Reset">

<form>

<p>What is your sex?

<input type="radio" name="sex" value="male"> Male

<br>

<input type="radio" name="sex" value="female"> Female

<p>Are you married?

<input type="radio" name="yesno" value="yes"> Yes

<br>

<input type="radio" name="yesno" value="no">No

</form>

Note that each group elements must have the same name to toggle radio buttons of the same group.

<form>

<p>Select you interests

<input type="checkbox" name="Computers>Computers

<br>

<input type="checkbox" name="Electronics">Electronics

<br>

<input type="checkbox" name="Sports">Sports

</form>