Yeah. Conceptually, you can think of the difference as whether or not there can be two copies of something. There can only be one copy of a Symbol, Fixnum, true

Yeah. Conceptually, you can think of the difference as whether or not there can be two copies of something. There can only be one copy of a Symbol, Fixnum, true, false, and nil. This means that true == true, and true.dup #=> error.