Im sorry, but is this a school question? if so, then you ought to make an effort and try to answer the questions yourself. That's the only way you learn something. [/edit]
To the question:
According to the IEEE definitions
abstraction is a view of a problem that extracts the essential information relevant to a particular purpose and ignores the remainder of the information.
and information hiding is the technique of encapsulating software design decisions in modules in such a way that the module's interfaces reveal little as possible about the module's inner workings; thus each module is a 'black box' to the other modules in the system.