Yes.  Access rights are very different. In England & Wales the Countryside and Rights of Way Act 2000 applies.  This gives rights of free access only in certain areas that are mapped, though you will be able to use rights of way elsewhere.  In Scotland, on the other hand, you can go anywhere that is not specifically excluded, provided that you behave responsibly.  For further information about the position in England see the Natural England website & for Wales see the Natural Resources for Wales website