Both, some birds like dunnocks, blackbirds, and thrushes prefer to feed on the ground others like robins, and finches prefer to be off the ground. make sure a ground feeder provides clear sight lines if there are cats about and a bird table has leafy cover close by. most birds will use hanging feeders with big enough perches.
When I had a garden it was a case of multiple hanging feeders , seed mix, sunflower hearts, peanuts Nyger seed and suet blocks, large ground feeder, two bird tables. One was used for corvids and had soaked crushed dried dog food, the other a seed mix, dried mealworms used to go on an old log and became robin central in addition a metalwork feeder and two bird baths one raised and one at ground level and in summer the contents of the slug traps tipped onto the lawn for the magpies.
As a result I could spend hours watching a wide range of birds including some less common. it really is worth going big on the feeder front. It will repay you every single day