Straight to the point.
From one side, a hobby is something you do for fun, it gives you temporal satisfaction, but you can put it on the side or get away from it when you want. It’s not something you want to do constantly or even for work.
On the other side, a passion is something you do to feel whole. Something that you miss with your heart, not just your hands. It is that "thing" that gives you continuous satisfaction and you don’t mind doing it for work or repeatedly.
Why is important to know the difference?
By knowing the difference between your hobbies and passions, it will make it easier to understand which you should pursue.
Andres example
From one side, a hobby of mine is playing the guitar, I know how to play it ( of course not in a professional way as Joe Satriani or Slash), but enough to play some tunes, have fun, burn some time, guide a quick thought and temporal satisfaction. Yet, I don't see myself playing guitar as a full-time job, I do not miss it with my heart nor with my hands.
On the other side, my passion is to Build Ventures, by building ventures I mean creating companies from scratch to top not only for me but also for corporations or individuals like you. I do not only have fun with it, I love it, every single piece of it, I could read, analyze, test, and find out business stuff for hours literally losing the sense of time; venture building gives me continuous satisfaction and I do not mind doing this for "work", as I do not feel working when doing Venture Building.
Painting example
From one side, a hobby of yours could be gardening, you know how to do it, it helps your releasing stress and also makes your garden looks nice. It gives your temporal satisfaction, but of course if you get yourself full of work you might just re-schedule your gardening time.
On the other side, your passion is Painting, every single thing related to painting gives you chills and you cannot stop thinking or talking about it, you might even say that sometimes you perceive you might annoy people by talking all the time about painting, and that doesn't matter, it's your passion. When not doing it you miss it with your heart and your hands. It gives you continuous satisfaction and you don't mind "working" on it repeatedly.
Note for me: Keep doing it Andres, as Aristotle said:
"We are what we repeatedly do. Excellence, then, is not an act, but a habit."
Big hug,
Andres