Not very much. "Hide" is the simple, everyday word. "Hide" can be used in two ways.
I can say "I'm going to hide," and it's understood that it means "I'm going to hide [myself]."
Or, I can say "I'm going to hide the cash in a safe place."
"Hide" and "conceal" suggest a deliberate action. "Obscure" suggests some accidental placement that blocks vision. When I came in from the cold, mist formed on my eyeglasses and obscured my vision.
"Obscure" has other meanings that relate to ideas such as "dark," "secret," or "hard to understand."