Reactive Programming is a form of Dataflow programming only. But its also a paradigm which is oriented around propagation of changes along with data flows
Like a example given on Wiki Page
a:=b+c would mean that a is being assigned the result of b + c, in the instant the expression is evaluated, and later, the values of b and c can be changed with no effect on the value of a. However, in reactive programming, the value of a would be automatically updated whenever the values of b and c change, without the program executing the sentence a := b + c again.
Which is the main difference between two of them. It binds the variables with expression and system reacts upon the changes in variable without running the expressions again and again.