What is the difference between the two/what does the 2nd mean? Question from (mostly) tech illiterate

https://preview.redd.it/6eci81f7x1ve1.png?width=1107&format=png&auto=webp&s=bcebbaf2da0e18c7dedca2e97700788b998ade9e

I got my hands on a relative's old laptop yesterday, and one thing I'm not sure on. This is put on the sticker on the laptop among some of the specs/sell pitch. What does the "max ssd memory" part mean? The laptop as is has 56.5 GB on the one C disk on it, so not sure what's the deal with 512 here.