Traffic Graph: definition of "in" and "out"

[mclaborn]

This is probably a silly question, but I haven't found the answer anywhere.
What is the definition of "in" and "out" when looking at the Traffic Graph?

My assumption is that "in" refers to traffic inbound to the pfSense box on the given interface and "out" is traffic outbound from the pfSense box on the given interface.

Can someone confirm?

[KOM]

That's it exactly.