ngl kinda seems like a r/GCSE question lol but the H+ ions are attracted by the charge through the water to the cathode where they gain electrons from the current to form H and covalent lay bond with other Hs form H2, and the rest of the water is a left as a hydroxide ion, OH-, which is turns into water and oxygen through the reaction: 4OH- -> H2O + O2 +2e-, so the oxygen is formed where the OH- ions react and the hydrogen is formed where the hydrogen ions gain electrons to become stable hydrogen molecules