Forms (and Html5)
http://www.w3.org/TR/html5-diff/ for an official status on html5 and differences to html4. From section 3.1:
type attribute now has the following new values:
in addition to
button, checkbox, file, hidden, image, password, radio, reset, submit, text,
as provided in html4.
The idea of these new types is that the user agent can provide the user interface, such as a calendar date picker or integration with the user's address book, and submit a defined format to the server. It gives the user a better experience as his input is checked before sending it to the server meaning there is less time to wait for feedback.
For example the
required attribute to indicate that the form is not to be submitted until a value is given. By adding this attribute to the customer name and delivery time fields, we allow the user agent to notify the user when the user submits the form without filling in those fields.
http://caniuse.com/ is a convenient always updated reference for what html5/css3 you can use in what environment.
Find two examples of html5 forms on the internet that make use of several of the new attributes described above.