For those of you not well versed in the James Bond franchise, M is the code name for the person who operates as the head of the Secret Intelligence Service in the United Kingdom.
It’s a rotating position, but their primary service in the story is as a voice of authority – albeit a friendly one.
They give Bond his orders, and while they have to sometimes bring the hammer down on the heroic agent when he acts a little too brashly, they are also willing to let a few things slide in recognition of his ability to consistently get the job done.