Java is a programming language and underlying technology that powers a range of computer programs. It runs on billions of computers worldwide, including mobile devices, and there are lots of apps and websites that won’t work unless you have Java installed. In the past few months, there have been some big security vulnerabilities in previous versions of Java, and Oracle, the company who creates it, has released a few new versions. The latest is (Version 7 Update 21). To find out your version, go to www.java.com and click on “Do I have Java?” Follow the prompts. If yours is an older version, you should update. It’s a free download.