It's illegal in the UK but the law was changed a few years ago (it may have just been changed back) so that the police wouldn't really bother you if you were smoking a small amount in private premises, not within a certain distance of any children or a school.
A lot of people turn a blind eye to it as it is quite common now among younger people, and even a lot of older people smoked it i
. Hash is normally smoked in a small pipe or a bong, but can also be mixed with tobacco and rolled into a cigarette. Some folks eat it in brownies, too. .