Oxygen, Carbon, Hydrogen
C2H6O, also known as Ethanol, is a polar molecule. You can see this from the 1st diagram, there is no clear line of symmetry. As you look at the 2nd diagram, you see the electronegativity of it’s atoms. The arrows point from the atoms with less electronegativity to the atoms with the higher electronegativity. As you can see, there are 3 Hydrogen atoms pointing to Carbon, 2 Hydrogen atoms pointing to the other Carbon, and a Carbon and Hydrogen atom pointing to the Oxygen atom. These arrows are simply depicting the electronegativity values within the molecule. Oxygen has an electronegativity value of 3.5 so Carbon, 2.5, and Hydrogen, 2.2, point to it. That is also why Hydrogen points to Carbon.