5 Lexical conventions [lex]

5.10 Tokens [lex.token]

1
#
There are five kinds of tokens: identifiers, keywords, literals,12 operators, and other separators.
Comments and the characters U+0020 space, U+0009 character tabulation, U+000b line tabulation, U+000c form feed, and new-line (collectively, “whitespace”), as described below, are ignored except as they serve to separate tokens.
[Note 1: 
Whitespace can separate otherwise adjacent identifiers, keywords, numeric literals, and alternative tokens containing alphabetic characters.
— end note]
12)12)
Literals include strings and character and numeric literals.