string, vector, array, sequence, t

A string is a specialized vector whose elements are of type character or a subtype of type character. When used as a type specifier for object creation, string means (vector character).

Abbreviating.

size — a non-negative fixnum, or the symbol *.

This denotes the union of all types (array c (size)) for all subtypes c of character; that is, the set of strings of size size.

Section 16.1 (String Concepts), Section 2.4.5 (Double-Quote), Section 22.1.3.4 (Printing Strings)