Magnetic Ink Character Recognition (MICR) is a technique that enables special characters printed in magnetic ink to be read and input rapidly to a computer. When a document that contains this ink needs to be read, it passes through a machine, which magnetizes the ink and then translates the magnetic information into characters.
MICR is used to verify the legitimacy or originality of paper documents, especially checks. MICR is used extensively in banking because magnetic-ink characters are difficult to forge and are therefore ideal for marking and identifying cheques.