“ATM machine” is an example of a redundant acronym — the M already stands for machine, so this phrase means “automatic teller machine machine.” Other examples:

• PIN number = personal identification number number
• GUI interface = graphical user interface interface
• ISBN number = International Standard Book Number number
• SAM missile = surface-to-air missile missile
• LCD display = liquid crystal display display
• CRT tube = cathode-ray tube tube
• HIV virus = human immunodeficiency virus virus
• SCSI interface = Small Computer System Interface interface
• AC current = alternating current current
• RPG games = role-playing games games

This goes for people, too. Jeb Bush’s nickname derives from his initials (J.E.B., for John Ellis Bush). So “J.E.B. Bush” stands for “John Ellis Bush Bush”.