assurance

Audit is always reasonable assurance. Other assurances can be either limited or reasonable - depending on what is being asked. So, it is impossible to give a reasonable assurance on a cash flow forecast as no one an predict future sales with any degree of assurance. However, if there had been a fire in a warehouse and inventory was destroyed the accountant might be able to give a reasonable assurance about value of the inventory lost, or with less work and a lower fee, might give a limited assurance saying that noting wrong was found with the client's calculations. A review engagement reviews a set of financial statements to see that they appear to have been prepared in accordance with IFRSs and appear to be OK (eg ratio analysis does not show unexplained changes). This requires less work than an audit (so cheaper) but is a long way short of the assurance given by an audit opinion.

respected sire what are the other assurances?

Assurance can be given on almost anything. Other than audit, and knowing the difference between limited and reasonable assurance, they are not on the F8 syllabus.