A Salaryman's life

Here in Japan, a typical office employee is called a salary-man. This is kind of a strange name, as anyone who works will be making a salary, right? So, what exactly is a salary-man in Japan? I think it can be replaced with the word "businessman", which again, is itself not that very descriptive, since anyone who does business with anyone else, i.e, any employee, is a businessman, right? Difficult questions like this pop into my mind when I have not had enough sleep...

I spotted this salary man, business-guy, man in a suit, whatever, at work in the street using a nearby city bench as a desk. Good luck business-salary-dude!