Keywords: defined within Java and its libraries, can not used as identifiers.
EXAMPLE FOR KEYWORDS:
Identifiers:
no keywords
case-sensitive
starts with letter, $ or _
no white space and special characters within
By Java common directives, in case the identifier consists of several words, they are written without separators but all words start with upcase letter whilst the first word starts with lowcase letter.
EXAMPLE FOR IDENTIFIERS: