Exactly how do internet work censors operate?

I’ve only worked one place that had computers, and they had a closed system with strictly limited access to certain content.

If a company allows an employee access to the internet, yet employs a censor or filter, how does that work?

Say you frequented a Q&A site. Is it realistic that the censor or filter would apply only to the questions, but not to the question details or answers? So you could ask a question about, say, “Yayas” then say “tits” in the details and discussion? That even social questions could contain the “7 words you can never say on television’?

Seriously, I’m curious about how this works.