In Clojure we can bind a piece of the code/data to a var (variable). To declare a global var we use a def special form (similar to let keyword in JS world).

(def my-list '(0 1 2))

We could also bind an expression to a var. Function range in our example returns numbers from 0 to 2 (0 1 2).

(def my-new-list (range 3))

We could also define a lexically scoped (local) bindings with a let special form. We declare them in square brackets by providing name and value pairs. a and b are only accessible in let scope wraped with parenthesis.

(let [a 1
      b 2]
  (+ a b)) -> 3

(+ a b) -> Syntax error