Python solution. Clean code with full comments. 95.96% speed.
\nclass Solution:\n    def findDifference(self, nums1: List[int], nums2: List[int]) -> List[List[int]]:\n        \n        set_1 = list_to_set(nums1)\n        s
```\nclass Solution:\n    def findDifference(self, nums1: List[int], nums2: List[int]) -> List[List[int]]:\n        \n        set_1 = list_to_set(nums1)\n        set_2 = list_to_set(nums2)\n        \n        return remove_same_elements(set_1, set_2)\n                \n# Convert the lists into sets via helper method.      \ndef list_to_set(arr: List[int]):\n    \n    s = set()\n    \n    for i in arr:\n        s.add(i)\n        \n    return s   \n\n# Now when the two lists are sets, use the difference attribute to filter common elements of the two sets.\ndef remove_same_elements(x, y):\n    \n    x, y = list(x - y), list(y - x)\n        \n    return [x, y]\n\n\n# Runtime: 185 ms, faster than 95.96% of Python3 online submissions for Find the Difference of Two Arrays.\n# Memory Usage: 14.3 MB, less than 51.66% of Python3 online submissions for Find the Difference of Two Arrays.\n\n# If you like my work, then I\'ll appreciate a like. Thanks!\n```
['Ordered Set', 'Python', 'Python3']