What is diff b/w FlowN and While Activities?

1.FlowN activity is replaced by the forEach activity in BPEL 2.0 projects,
  forEach executes its contained scope N times,
2.The flowN activity creates multiple flows equal to the value of N,
  which is defined at run time based on the data available and logic within the process.
  Index variable increments each time
3.while executes its contained scope repeatedly until a condition is no longer true.