In the James Bond series, "M" is the head of the MI6, the British Secret Intelligence Service. M oversees Bond's missions and provides him with essential information and resources. The character has been portrayed by various actors, including Bernard Lee, Judi Dench, and Ralph Fiennes. M is known for their authoritative demeanor and often serves as a mentor to Bond. The character plays a crucial role in shaping the narrative, balancing the excitement of espionage with the responsibilities of national security. M's decisions often impact the course of Bond's adventures and the overall mission objectives.