From http://www.w3schools.com (Copyright Refsnes Data)

HTML 5 <button> tag

Definition and Usage

Defines a push button. Inside a button element you can put content, like text or images. This is the difference between this element and buttons created with the input element.

Differences Between HTML 4.01 and HTML 5

HTML 5 has a new attribute: autofocus

Example

Source	Output
<button>Click Me!</button>

Attributes

4: indicates if the attribute is defined in HTML 4.01
5: indicates if the attribute is defined in HTML 5

Attribute	Value	Description	4	5
autofocus	true \| false	Makes the button focused or not, as the page loads		5
disabled	disabled	Disables the button	4	5
name	button_name	Specifies a unique name for the button	4	5
type	button reset submit	Defines the type of button	4	5
value	some_value	Specifies an initial value for the button. The value can be changed by a script	4	5

Standard Attributes

class, contenteditable, contextmenu, dir, draggable, id, irrelevant, lang, ref, registrationmark, tabindex, template, title

For a full description, go to Standard Attributes in HTML 5.

Event Attributes

onabort, onbeforeunload, onblur, onchange, onclick, oncontextmenu, ondblclick, ondrag, ondragend, ondragenter, ondragleave, ondragover, ondragstart, ondrop, onerror, onfocus, onkeydown, onkeypress, onkeyup, onload, onmessage, onmousedown, onmousemove, onmouseover, onmouseout, onmouseup, onmousewheel, onresize, onscroll, onselect, onsubmit, onunload

For a full description, go to Event Attributes in HTML 5.