Java
Other than a few syntactical similarities (both languages borrow heavily from C syntax)
Java and
JavaScript are completely different technologies. The similarity in their names was a marketing ploy by
JavaScripts creators to try and ride the coat-tails of
Java, which was the hot new language when
JavaScript was created.
Core Java refers to the core set of classes available in the Java programming language. (Essentially, the most important classes that a programmer can count of being available no matter what.)
Java is a class-based object oriented, computer programming language created by Sun Microsystems and currently owned by Oracle. It is a full featured, compiled programming language. It's used to create all kinds of software, but the key point here is that it is turned into byte-code by the Java Virtual Machine before it is run on the computer. By default, Java has access to everything on the machine. It can make changes to the OS, write files, access the network--you name it.
JavaScript
JavaScript is a proto-type based object oriented scripting language that was invented by Netscape in the mid 1990s. It's used to add dynamic functionality to web pages. As a scripted language,
JavaScript is not compiled. Rather, its source code is sent as text to the browser, which then parses the file and acts accordingly.
JavaScript is extremely constrained, due to security concerns, and cannot access your hard-drive, with the exception of a few, very limited locations.
