JavaScript is embedded code on a webpage that can perform any number of functions such as modifying page elements dynamically, or making calls to retrieve information live without refreshing the page. JavaScript is a staple of the modern web and used on almost every modern website. However, with increasing usage and complexity, Javascript can fail on a page due to coding problems, incorrect versions or loading issues. Sometimes failures can interrupt proper execution of a page and break other functions, and so Javascript errors should generally be examined to understand the cause and what it's impacts are .