Mainframes -LRB- often colloquially referred to as Big Iron -RRB- are computers used mainly by large organizations for critical applications , typically bulk data processing such as census , industry and consumer statistics , ORGANIZATION@1 , and financial transaction processing .

Mainframes -LRB- often nicknamed big iron -RRB- are large and expensive computers used mainly by government institutions and large companies for things like data processing , industry and consumer statistics , and financial transaction processing .
