Definition: Encryption is a means of concealing the actual content and meaning of something by substituting other values according to some predefined formula. This can vary from straight substitution through formula substitutions to actual code table lookups.
In normal use the more complex the formula used for the conversion and the less relationship that there is between specific encrypted values and the original source then the harder it becomes for anyone to decrypt the content of the message.
With Javascript encrypted web pages the exact encryption method used is totally irrelevant as the web page also needs to include the script to decrypt the page or the web browser can't decrypt and display it. This makes even the most complex encryption method just as easy to bypass as the simplest substitution.
