The following is taken from the 1963 revision of IBM Data Processing Machine Functions, a booklet which describes the functions performed by the IBM machines of that time.

The IBM card has 80 vertical columns, each of which accommodates a hole (or holes) representing a single number or letter. Card punching is the basis method of converting source data into IBM punched cards. The operator reads a source document and presses the keys of the keyboard to puch the cards. The machine feeds, positions, and ejects the card automatically.