I am newbie at bitcoin and always i saw a change in bitcoin value. What are the factors that affects the change in bitcoin value? Is it also same like real money? Like if value of Gold decreases then value of US dollar increases and vice versa.

As what others said, supply and demand that causes the bitcoin price increases, and it also decreases because there so many people and companies big/small accept bitcoin already, so there will always change if price but the thing is it always increase and growing.