Some functions of a mainframe computer are bulk data processing, centralized computing and platforms for e-commerce hosting and development. A mainframe computer got its name because the earliest ones were housed in large metal frames.
Mainframes were introduced in the late 1950s, and at that time they were stored in huge metal cabinets in some central location within a company. They accepted punched cards and paper tape to transfer data. The applications of the early mainframes included supporting back office functions like customer billing. By the 1970s, mainframes were able to support interactive user interfaces and could support hundreds of users along with batch processing. By the 1990s and into the 2000s, mainframe computers evolved and phased out green-screen terminal access in favor of Web-style user interfaces.
While mainframes of today may not be as large as those in past years, they are still useful in a number of business applications. Bulk data processing, for example, is made easier by a mainframe because an employee can set up a program to run a job with out any human intervention. Centralized computing is an efficient way to keep all the Information Technology, or IT, components all in one area. Finally, with more and more businesses moving towards e-commerce, a mainframe is an efficient way to support hosting and development of the business.