Q: Disable Split View

I just updated my iMac to El Capitan from Yosemite.  Whenever I drag window title bars quickly to the top of the screen, the screen changes to show me the desktop and a plus-thingy at right.  I don't know if this is called "Split View" or "Mission Control," but it annoys the heck out of me and I want to DISABLE it.  But how?

In other words, I want to be able to drag window title bars quickly to the top of my screen WITHOUT ANYTHING HAPPENING AT ALL.  I may wish to invoke Split View or Mission Control another way, but I definitely do NOT want it to auto trigger just by my accidentally moving windows to the top of the screen.  I can't imagine I am alone in thinking this way.

I look forward to your replies.

Thank you.