The syntax of Lisp is made up of the same fundamental data types as you use when writing Lisp programs. `(+ 1 2 3)` is both a Lisp expression that evaluates to

The syntax of Lisp is made up of the same fundamental data types as you use when writing Lisp programs. `(+ 1 2 3)` is both a Lisp expression that evaluates to 6 and also a list containing four items, the symbol `+` and the numbers 1, 2, and 3. In general, we can say that the Lisp language is very good at manipulating the same data types that the syntax of Lisp programs is made from. This makes it very easy to write Lisp programs that swallow up Lisp programs as raw syntax, analyze Lisp programs syntactically, and/or spit out new Lisp programs as raw syntax.