Eek. how embarrassing, this “title” due simply to the quantity of my bloviations here, not the quality, I assure you.
So to further bloviate, 
Javascript is a scripting language that makes it possible for web pages to do automated stuff, like logging into a website or deciding which advertisement show you. Java is a whole programming platform. here’s a website that gives an explanation- Java vs. JavaScript: Similarities and Differences | HTML Goodies