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."

"My vision was obscured by the bush". "His pistol was concealed within his jacket". "The squirrel hides the acorns". "We found a hidden passage way" Hide and conceal are quite inter-changeable. Hide is much more common in everyday speech though. Hope that helps :)