Answer:

A sorting algorithm is said to  be stable if the relative order is maintained after the list has been sorted. For example: [1,3a,3b,2]->[1,2,3a,3b] this is stable. 

Bubble sort is stable because of the strict < comparison in the code (elements are only swapped if they are less than the other element, so equal elements are not swapped and the relative order is maintained). Using <= would make it unstable.

Feedback: 

The ‘>’ comparison is being done, elements are swapped if the element on the left is greater than the one on the right.