Question about SQL Table Transformation Exercise Correlated Subqueries II


Hi, I’m new to SQL and I have a question about what the code in the example is doing (link to exercise:

My biggest confusion is coming from the line: FROM flights f"

From the sidebar, I can see flights is a table in the database but that f is not. From what I can understand, f is an alias for the table flights in order for us to compare rows, but I want to make sure I am understanding this correctly.

So my question is, what is SQL doing with that statement?