The IBM Selectric typewriter was a highly successful model line of electric typewriter

Typewriter

A typewriter is a mechanical or electromechanical device with keys that, when pressed, cause characters to be printed on a medium, usually paper. Typically one character is printed per keypress, and the machine prints the characters by making ink impressions of type elements similar to the pieces...

s introduced by IBM

IBM

International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

 on July 31, 1961.

Instead of the "basket" of individual typebars that swung up to strike the ribbon and page in a traditional typewriter, the Selectric had a type element (frequently called a "typeball") that rotated and pivoted to the correct position before striking. The type element could be easily changed so as to print different fonts in the same document, resurrecting a capacity that had been pioneered by the Blickensderfer typewriter

Blickensderfer typewriter

The Blickensderfer Typewriter was designed by George C Blickensderfer in 1893. It was originally intended to compete with Remington desk typewriters, but ended up being known for its portability. Blickensderfer's typewriter contained only 250 parts compared to the 2,500 parts of a standard...

 sixty years before.