Afraid is what you always fear about. Afraid of black icecream eating cats, or darkness. But if i jump out of knowhere infront of you shouting, you will be scared.

There is a slight difference between the 2 words. Example: I'm afraid of spiders and sharks. I am scared of getting a terminal illness like cancer.

According to the OED, 'scared' : is very common in informal speech and is often used to describe small fears, 'afraid' : is more formal and less common; BUT this is true only when they are used to mean the feeling of fear. ............................ , 'afraid' has broader meaning/usage, more than just feeling fear. 'Afraid' is also used to mean 'worried' and in this case, 'afraid' is more commonly used than 'scared'. The idiom 'I'm afraid (that)' means 'I'm sorry to tell you (that)' and is used to introduce apologetic refusals and bad news (I'm afraid that I can't help you). In this case, scared is hardly used. Another important point is that 'afraid' is one of the adjectives that are not usually used before a noun in attributive position John is afraid (but never John is an afraid man). On the contrary, 'scared' can be used in attributive position eg. a scared child' ................................... http://www.proz.com/kudoz/English/other/338121-afraid_scared.html

There's a little difference between them: afraid: frightened because you think that you may get hurt or that something bad may happen. scared: something or something happening makes you frightened.

They mean the same thing. Saying "I'm afraid." and "I'm scared." is the same thing.