Clojure extends the syntax of Lisp to include first class support for data structures other than lists (vectors, sets and maps). Vectors are the [ ] structure

Clojure extends the syntax of Lisp to include first class support for data structures other than lists (vectors, sets and maps). Vectors are the [ ] structure you see. You can use ( ) to specify a number of function bodies which differ on arity e.g: (defn foo ([x] x) ([+ x y]) So it's not to stand out more, rather it's extending the Lisp syntax to make items other than lists "first-class" whilst retaining the homoiconic properties of Lisp.