When the evaluator is applied to a symbol the computed value of the form is the value associated with the symbol in the current environment. Basically this means that to get the value of a variable you simply write its name. For example,
rep-version ⇒ "1.0"
this extract from a Lisp session shows the read syntax of a form to
get the value of the variable
rep-version and the result when
this form is evaluated.
Since forms are evaluated within the current environment the value of a variable is its most-recent extant binding (with slight differences for lexical and special variables). See Variables.
If an evaluated symbol has no current binding, an error is signalled.