Everyday mail The virtual address
A street address run by a company that receives post on your behalf. Depending on the service, letters are scanned, forwarded, held for collection or some mix of the three.
Customers, suppliers and banks are the ones who usually write to it, and it is the address that ends up on an invoice, a website or a business card.
Legal notices The registered agent
A person or company named on a business's state filings to accept legal papers and official notices on its behalf. Courts, state offices and anyone serving a lawsuit write here.
It is a role a business is asked to fill when it forms an entity, and whoever fills it is expected to be reachable at that address.