Is Core-Mark a distributor?

Excuse me, could you please clarify for me if Core-Mark is indeed a distributor? I've been trying to gather information on their business model and operations, but I'm still a bit unsure about their exact role in the market. Could you provide me with some insight into whether they function as a distributor, and if so, what products or services they distribute? I'd greatly appreciate any clarification you can offer on this matter.