How is the difference between Product Marketing and Product Manager?

I see the PMMs job as connecting the product teams to end-users and to the market. PMMs have a pulse on what is going on competitively, what is trending, and brand perception the market. PMMs also talk to a lot of customers for customer stories, blog posts etc. so they have a good perspective on what successful users look like. 

I see the PMs job as interpreting user feedback and rallying the team to strategically build features that enhance the user experience and also align with the goals of the company. PMs also typically keep their teams working in sprints which emphasizes frequent shipping and lots of opportunities for learning and adjustments to be made along the way.

PMs work majority internal-facing, PMMs have quite a mix and also collaborate with a ton of different cross-functional teams, I tend to see them as the connector/translator between all the teams!