What is "onblur"
The event onBlur occurs when an object loses focus. Technically all elements can receive a status of :focus but according to the website w3schools there are some elements that cannot receive this status, being they <base>, <bdo>, <br>, <head>, <html>, <iframe>, <meta>, <param>, <script>, <style>, and <title>. Like other events, Blur serves to trigger some function within the DOM for an application (website and the like).