A type="checkbox" allows users to select (or deselect) zero, one, or more, options.
When grouping checkboxes, as with ‘radio buttons’ the name="" should be the same for each element option, while the value="" should be unique to each element.
NOTE: Displayed text should appear AFTER each checkbox element.
As with radio buttons, you can use the checked attrubite to pre-select checkboxes.
<form action="http://www.example.com/profile.php">
<p>Please select your favorite music service(s):
<br />
<input type="checkbox" name="service" value="itunes" /> iTunes<br />
<input type="checkbox" name="service" value="lastfm" /> Last.fm<br />
<input type="checkbox" name="service" value="spotify" checked /> Spotify<br />
</p>
</form>