Rome is full of fountains. If there’s a street anywhere in the city that doesn’t have some kind of fountain I don’t think I’ve ever seen it. They range from the famous fountains designed by Bernini and others – the ones you’ll find in the tourist guide books – to the everyday drinking fountains that are found on almost every street in Rome.
And yes, it is safe to drink the water. The trick is to cover the large hole with your finger – that makes the water come out of the smaller hole further up the pipe, making it easier to drink. Or just buy a bottle of water and refill it from the fountains as your walk around Rome.