Learning a new word "direct report"

I always used "subordinate" to express people under their boss. For example, when I have to explain my work experience and mention one of them, I say "I was a manager of training department and had over 30 subordinates."

But today, I learned "direct report". I heard it for the first time. I wonder which is often used. And I wonder I can say "I had over 30 direct reports".

By the way, a document of work experience is "resume", isn't it? But I have heard that people use "CV" a few times. According to a dictionary, "resume" derives from French and "CV" derives from Latin. I wonder native speakers often use both words. Or it depends on their country?