It's a silly and meaningless question. There's nothing that is officially or even commonly referred to as a "magic word" in Java. Whoever asked the question needs to stop trying to be clever and clarify what he's asking.
There is a post on geekinterview which says that Magic Words are deprecated reserved (key) words like goto and const.
But considering that searching "magic word java" yields just one positive result ,I don't think it( the term "magic word" for goto and const) is used much.
Leave it as it is now - a reserved word that you can't use.
In case you don't know, there's a history behind goto. It has been used in a number of programming languages, for example in BASIC, and at a certain moment people realised that programming with goto-statements made their programs very hard to follow - using goto a lot makes your program into spaghetti code. Computer science professor Esger Dijkstra noticed this in 1968 already, and wrote a famous paper titled "Go To Statement Considered Harmful".
The designers of the Java programming language decided that Java should not have such a "goto" statement, so they decided to make it a reserved word that cannot be used.
CAFE BABE is the magic number ..which is present at the first line of the .class file.it will tell to jvm that the code which is compile is correct according to the version and other internal detail ..after rhat CAFE BABE next bits are present for version ckeck and sub version check