What it does
Five networks, one queue. Write once, choose where it goes and when, and let it publish while you are doing something else. The dashboard is where you go afterwards to see what went out and what happened to it.
Why it is not another calendar
The interface most people use is an assistant, not a form: you say what you want posted and when, and it does the scheduling. Every social tool is a grid of boxes to fill in, and filling them in is the part nobody wants to do.