Use of Computers in Banks

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Any neighborhood bank offers a variety of services, including access to your personal and business account information, advice on investments, funds withdrawals from either a live or automated teller, and funds transfers completed over the Internet. Computers support all of these functions and services, and it takes different types of computers to make it all happen seamlessly.

Mainframe Computers

While many companies have downsized their computers, your bank's workhorse is still the mainframe. Often called "big iron," the mainframe is the backbone of any bank's operations because it performs all the following, simultaneously:

  • Houses all customer account data.
  • Performs complex analysis of constantly changing financial markets.
  • Keeps track of all the bank's product offerings and their associated interest rates and earnings.
  • Communicates with other mainframes at branch locations around the world.

That's a lot to ask a computer to do, but a mainframe is designed to multitask, routinely performing more than one million transactions every second.


  • According to the American Bankers Association, the U.S. has 68,000 banks supported by 97,000 branches.


The automated teller machine (ATM), which was introduced in the 1970s, liberated the typical bank customer from that last-minute race to get to the bank before it closed. (Remember this was before the Internet when you checked your account balance either in person with a teller or by phone, both of which required the bank to be open.) Using an ATM, customers were finally able to check account balances, withdraw cash and eventually deposit cash and checks, make transfers between accounts and make loan payments. The individual computer units inside each ATM are linked to the bank's mainframe, where all the data are stored and coordinated, and by interbank ATM networks, which is why you can only withdraw your bank's daily cash limit at one ATM; you'll be denied if you move to any other ATM and try to do it again.

Teller Terminals

Servicing the varied national and international needs of today's bank customers requires a teller able to communicate as much with the outside world as with the mainframe. All of this communication happens from the individual teller terminal. Teller computer terminals provide access to business and personal overseas accounts and process wire transfers and bill payments to the bank's proprietary credit cards and any other bills, such as your electric bill, that the bank offers to facilitate at its location.

Digital Scanners

Whether the scanner is stand-alone or attached to a larger computer, digital imaging has come to play a role in modern banking. The attacks of 9/11 in 2001 resulted in an unprecedented closing of American airspace. As a result, paper checks between federal reserve locations for processing were delayed. Congress ensured that would never happen again by making digital scans of checks as legally viable as paper checks. Now banks and their customers use check scans routinely for deposits and transfers, making the digital imaging function a major player in today's computerized banking.


  • What we think of as money has evolved from beads and shells to currency, to digital credits. From the printing press to the Internet, technology has played a part every step of the way in the evolution of banking, ultimately creating the electronic money we use today.

Biometric Devices

American Express and BBVA are two U.S. financial institutions that jumped first into biometric identification of customers. Press your thumb to the digital device and the tiny computer inside verifies your identity using your unique fingerprint. With increasing availability of this technology, these print readers will soon be standard computer technology for banks internationally.


About the Author

An attorney for more than 18 years, Jennifer Williams has served the Florida Judiciary as supervising attorney for research and drafting, and as appointed special master. Williams has a Bachelor of Arts in communications from Jacksonville University, law degree from NSU's Shepard-Broad Law Center and certificates in environmental law and Native American rights from Tulsa University Law.