"Hello" is the standard form of greeting, whereas "hi" is an informal word.

hello for everyone and hi for nearest person just like u

"Hello" is the standard form of greeting, whereas "hi" is an informal word.

both of them give the same meaning .... but Hello is said to some person u don't know him before .....Hi is said to person that u know or ur friend ....etc that was my opinion and thnx :)

I think that hello is more formal then hi,because for my experience I use hello by phne or with new people and hi talking to my relatives or my friends.