What properties can I use with event.target?

If you were to inspect the event.target with firebug or chrome's developer tools you would see for a span element (e.g. the following properties) it will have whatever properties any element has. It depends what the target element is:

event.target: HTMLSpanElement

attributes: NamedNodeMap
baseURI: "file:///C:/Test.html"
childElementCount: 0
childNodes: NodeList[1]
children: HTMLCollection[0]
classList: DOMTokenList
className: ""
clientHeight: 36
clientLeft: 1
clientTop: 1
clientWidth: 1443
contentEditable: "inherit"
dataset: DOMStringMap
dir: ""
draggable: false
firstChild: Text
firstElementChild: null
hidden: false
id: ""
innerHTML: "click"
innerText: "click"
isContentEditable: false
lang: ""
lastChild: Text
lastElementChild: null
localName: "span"
namespaceURI: "http://www.w3.org/1999/xhtml"
nextElementSibling: null
nextSibling: null
nodeName: "SPAN"
nodeType: 1
nodeValue: null
offsetHeight: 38
offsetLeft: 26
offsetParent: HTMLBodyElement
offsetTop: 62
offsetWidth: 1445
onabort: null
onbeforecopy: null
onbeforecut: null
onbeforepaste: null
onblur: null
onchange: null
onclick: null
oncontextmenu: null
oncopy: null
oncut: null
ondblclick: null
ondrag: null
ondragend: null
ondragenter: null
ondragleave: null
ondragover: null
ondragstart: null
ondrop: null
onerror: null
onfocus: null
oninput: null
oninvalid: null
onkeydown: null
onkeypress: null
onkeyup: null
onload: null
onmousedown: null
onmousemove: null
onmouseout: null
onmouseover: null
onmouseup: null
onmousewheel: null
onpaste: null
onreset: null
onscroll: null
onsearch: null
onselect: null
onselectstart: null
onsubmit: null
onwebkitfullscreenchange: null
outerHTML: "<span>click</span>"
outerText: "click"
ownerDocument: HTMLDocument
parentElement: HTMLElement
parentNode: HTMLElement
prefix: null
previousElementSibling: null
previousSibling: null
scrollHeight: 36
scrollLeft: 0
scrollTop: 0
scrollWidth: 1443
spellcheck: true
style: CSSStyleDeclaration
tabIndex: -1
tagName: "SPAN"
textContent: "click"
title: ""
webkitdropzone: ""
__proto__: HTMLSpanElement

event.target returns the DOM element, so you can retrieve any property/ attribute that has a value; so, to answer your question more specifically, you will always be able to retrieve nodeName, and you can retrieve href and id, provided the element has a href and id defined; otherwise undefined will be returned.

However, inside an event handler, you can use this, which is set to the DOM element as well; much easier.

$('foo').bind('click', function () {
    // inside here, `this` will refer to the foo that was clicked
});

window.onclick = e => {
    console.dir(e.target);  // use this in chrome
    console.log(e.target);  // use this in firefox - click on tag name to view 
}  

take advantage of using filter propeties

e.target.tagName
e.target.className
e.target.style.height  // its not the value applied from the css style sheet, to get that values use `getComputedStyle()`