Python 3: Readable solution with comments
```\nclass Solution(object):\n    def isRectangleOverlap(self, rec1, rec2):\n        # TIME and SPACE Complexity: O(1)\n\t\t\n        #Funtion checking if coord
```\nclass Solution(object):\n    def isRectangleOverlap(self, rec1, rec2):\n        # TIME and SPACE Complexity: O(1)\n\t\t\n        #Funtion checking if coordinate of Rec2 overlapped Rec1;\n        def checkOverlapping(rec1_left, rec1_right, rec2_left, rec2_right):\n            \n            rec2_StartingCoordinate = max(rec1_left, rec2_left)\n            rec1_EndingCoordinate = min(rec1_right, rec2_right)\n            isOverlapped = rec2_StartingCoordinate < rec1_EndingCoordinate\n            \n            return isOverlapped\n        \n        \n        #All Horizontal coordinates of Rec1 and Rec2;\n        rec1HozlLeft = rec1[0]\n        rec1HozlRight = rec1[2]\n        rec2HozlLeft = rec2[0]\n        rec2HozlRight = rec2[2]\n        \n        #All Vertical coordinates of Rec1 and Rec2;\n        rec1VerBottom = rec1[1]\n        rec1VerTop = rec1[3]\n        rec2VerBottom = rec2[1]\n        rec2VerTop = rec2[3]\n        \n        # 1st Check the Horizontal coordinates if Rec2 is overlapped Rec1;\n        ## 2nd Check the Vertical coordinates if Rec2 is Overlapped Rec1; \n        ### return True if both Horizontal and Vertical are Overlapped\n        return checkOverlapping(rec1HozlLeft, rec1HozlRight, rec2HozlLeft, rec2HozlRight) and \\\n                checkOverlapping(rec1VerBottom, rec1VerTop, rec2VerBottom, rec2VerTop)
['Math', 'Geometry', 'Python', 'Python3']