Say you have a graph of say $y=mx+b$, with $x$ on the horizontal axis and $y$ on the vertical axis. You need to give the graph a title, would you say:

This is a graph of "$y$ versus $x$?"

or

This is a graph of "$x$ versus $y$?"

Is the independent variable always first like $independent$ versus $dependent$, when you say versus or, the other way around?

Tried general searching, and doing a CTRL+F for "versus" on graphing related Wikipedia pages but couldn't find anything on this, hopefully im not the only one who has been confused by this?

To clarify, the problem im stuck on because of this, and from other encounters with this terminology, the side of "versus" a variable is on, is related to which variable is the independent variable and which is the dependent variable. That is the relationship i am asking about. Not whether $y$ is a function of $x$ or vice versa.