For the first 3 decades of computing, there were no screens and no interactive use of computers. To get information into a computer, both software and data, required the use of punch cards. They look like this:
Here's how they worked. To punch cards, a person sat at a keypunch machine and typed letters and numbers. The machine punched square holes in the card, making chads. (Keypunches, being heavy-duty machines, never produced "hanging chads", like the hand-powered voting machines of the 2000 US election.) The punched cards were collected together and given to a computer operator, the dude in this picture. He fed the cards into a card reader, the gray box to the right of the telephone. (Where is the computer in this photo? Did you guess the tape drives? The computer is in the gray boxes under the clock on the back wall.)
This was a cumbersome way to use computers.
