Early method of data storage used with early computers. Punch cards also known as Hollerith cards and IBM cards are paper cards containing several punched holes that where originally punched by hand and later by computers that represents data. These cards allowed companies to store information and be able to access that information by entering the card through the computer. The picture shows an example of what a punch card looks like.
These cards are known to be used as early as 1725 for use with controlling textile looms. The cards were later used to store and search for information in 1832 by Semen Korsakov. Later in 1890 Herman Hollerith developed a method for machines to record and store information onto punch cards to be used for the US census. He later formed the company we know as IBM today.
Punch cards were the primary method of storing and retrieving data in the early 1900s, however began being replaces by other methods in the 1960s and today are rarely found or used with computer storage.