What are the capabilities of Shopify customer accounts?

I’m new to Shopify and I’m trying to understand the scope of what is possible in the customer authenticated experience. Specifically, I’m interested in selling a product where we ship a customer a lab test, they send it back to the lab and then they receive results from us (via a pdf, for example).

Is it possible for customers to log into our Shopify site and receive the pdf and/or ui of their personal results within the site?

I imagine there is documentation related to this, though I haven’t been able to find it. Thanks for the help!