ASUS extended model number

Question

Many ASUS laptops have a suffix added to their model number. I'm wondering what this stands for and what the differences between machines with different suffixes can be?

For instance on my laptop, it says BU401LA-FA273G. According to the ASUS website, BU401LA is the model number. Then what does the FA273G mean? In general what can be the differences between my BU401LA-FA273G and, say, a BU401LA-FA366G?

(In particular I'd like to know whether the charging port can differ but please give a general answer so it may be of use to others.)