Marketing Management is the broader discipline. It covers strategy, brand positioning, target groups, campaigns across channels, lead generation and budget control.
AI Visibility / SEO & GEO focuses on one specific outcome: being found in search engines and cited in AI-generated answers.
In practice the two work together. Marketing Management defines what you want to be known for and for whom. SEO and GEO make sure that this message is discoverable and quotable in Google, ChatGPT, Perplexity, Gemini and similar systems.