Students and second homeowners
If you split your time between two addresses, for example if you're a student and have a home address and a term address, or if you own and live in more than one property, you can register to vote at both addresses (as long as they're not both in the same council area.)
At local elections you can vote in both places.
At national elections, like a general election, you can only vote in one place, but you can choose which place you vote in.
Voting in more than one place at a national election or referendum is a criminal offence.