encapsulation vs abstraction

Hi friends,
In context to object oriented programming: -

• What is the difference between data abstraction and data encapsulation?Are they both implementing information hiding?
• 'A class encapsulates the methods and data members defined in it'. So, is encapsulation not representing a simpler view of a class(in terms of its functions and data members)?How does the concept of security comes up then?
• Actually it should be data abstraction representing secure data access since it is hiding low level details of implementation. Am I right?