Hollerith cards were rectangular cards that were used to store data on punched holes. These cards were widely used in the early days of computing to store information that could be quickly and easily retrieved. However, with the rise of more advanced computer systems, Hollerith cards have become obsolete. In modern times, the term punch card or computer card is generally used as a synonym for Hollerith card. Other synonyms for Hollerith cards include tabulating cards, IBM cards, and punched cards. Despite the fact that Hollerith cards are no longer in use, they remain an important part of computer history and continue to be studied by computer historians and enthusiasts today.