Data Abstraction = Data Encapsulation + Information Hiding
Encapsulation is seen as the bundling of data with the methods that operate on that data. This means, that data can only be accessed
via these methods. Information hiding on the other hand is the principle, that some internal information or data is "hidden", so that it can't be accidentally changed from outside.
Finally, data abstraction is present, if both data hiding and data encapsulation is used.