Mainframe is a class of computers that controls many connected uses and has a high volume of transactions hence providing more reliable performance. Client-server and mainframe network promotes great security of the computer network and has more control and hence can see what every computer is doing Given these comments regarding mainframes--why use mainframes? What are they used for today? Please give more pacific answer for this question.  Paper can be 1 to 2 pages long Please cite reference and list address of website visit.