I've been a Salesforce administrator in the past. Here are some things I "built" in Salesforce. (I put "built" in quotes because I'm not a construction worker and the effort that you need to put into making what I've done here is minimal compared to, say, constructing a deck for your house.)
I made this custom object for a previous employer. It keeps track of a variety of information. There are validation rules and workflows at work here (even though you can't see them in a static image). Also, see that button that says "Conga"? That's a vendor I sourced for my company that uses Salesforce information to created PDFs on-demand (like our vendor newsletter). I made that button.
I also created an entire and robust training curriculum for my organization.
Now you know.