What is the difference between linear data structure and non-linear data structure ? I know it is a pretty straightforward question but how would go on defining it properly ? There is NO standard way of defining it ( at least from what I have come across the internet )

For example,if you say,yeah ! you know we can define linear data structure as something that stores the elements in contiguous manner,one after another. Ok that's good,but if you think about this definition,heap becomes a linear data structure then,isn't it ? You store heap in an array,and you define it a complete n-ary tree (complete binary tree in case binary heap )

If we define it in terms of successor and predecessor,we can say that linear one have "unique" successor and predecessor,and non-linear don't .

To sum up,what's the right way of defining?

Looking for your views