The role responsible for how BIM actually gets delivered - writing and enforcing the BEP, defining office and project templates and standards, training staff, and making sure the model data a project produces actually satisfies the client's EIR. A BIM Manager operates at a strategic level: firm-wide standards, software rollout, process improvement, sometimes managing a team of BIM coordinators across several projects.
It is a genuinely different job from a BIM Coordinator, who works inside one project's day-to-day model coordination - though on smaller firms and projects, one person often ends up wearing both hats.