I think that's why Scott Hanselman started this series https://www.hanselman.com/blog/new-youtube-series-computer-t...

You sure you didn't have a computer architecture course? Most CS programs it is a required course

I did (actually it was last semester) but they didn’t do basic definitions, it came with an assumption you knew what the parts of a computer were.

That's unfortunate. Luckily there are tons of good resources online like OSSU https://github.com/ossu/computer-science

What is a required course?

In American terminology, individual classes are called "courses". This particular course is likely "required" as one of the steps in a Computer Science "major".

a required module of a course

It could be meant not in a way of "this is ram vs this is disk", but "we have a 1tb dataset, what kind of a server do we need?", and the person not knowing enough about databases to think they need 1tb of ram to be able to run it.

But can you really be, let's be modest, around the baseline of developer competence not knowing the difference between RAM and disk space?

Hard to believe to me.