[Pro Tools Noob Sm. Caulk]

I've been looking at a new interface, and this term always confuses me. I saw this interface that said 18X24 simul in/out. I could only find 10 xlr inputs a 2 line level inputs. As for the output I couldn't find 24 outputs, analog or digital. I think I only saw 8 TRS outputs and some spdif and adat digital stuff.

HOW DO I REALLY FIGURE OUT HOW MANY INPUTS AND OUTPUTS AN INTERFACE HAS????? PLease help