When an HTML event occurs, HTML DOM allows JavaScript to respond accordingly. Some of these HTML events are:
Onclick
Occurrence: when element is clicked.
Ondblclick
Occurrence: when element is double-clicked.
Onfocus
Occurrence: when an element gets focus such as button, input, textarea etc.
Onblur
Occurrence: when form loses the focus from an element.
Onsubmit
Occurrence: when form is submitted.
Onkeydown
Occurrence: when key is being pressed.
Onkeypress
Occurrence: when user presses the key.
Onkeyup
Occurrence: when key is released.
Onload
Occurrence: when document, object or frameset is loaded.
Onunload
Occurrence: when body or frameset is unloaded.
Onscroll
Occurrence: when document is scrolled.
Onresize
Occurrence: when document is resized.
Onreset
Occurrence: when form is reset.
Onmouseover
Occurrence: when mouse is moved over an element.
Onmouseout
Occurrence: when mouse is moved out from an element (after moved over).
Onmousedown
Occurrence: when mouse button is pressed over an element.
Onmouseup
Occurrence: when mouse is released from an element (after mouse is pressed).