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