A keyword is a word whose meaning is defined by the programming language.
Java Keywords and Reserved Words:
abstract class extends implements null strictfp true
assert const false import package super try
boolean continue final instanceof private switch void
break default finally int protected synchronized volatile
byte do float interface public this while
case double for long return throw
catch else goto native short throws
char enum if new static transient
An identifier is a word used by a programmer to name a variable, method, class, or label.
Keywords and reserved words may not be used as identifiers.
An identifier must begin with a letter, a dollar sign ($), or an underscore (_); subsequent characters may be letters, dollar signs, underscores, or digits.
Some examples are:
foobar // legal
Myclass // legal
$a // legal
3_a // illegal: starts with a digit
!theValue // illegal: bad 1st char
Identifiers are case sensitive.
For example, myValue and MyValue are distinct identifiers.