Something happens on the other side of the world and we hear news about it within moments through the media. News is anything! Anything and everything that happens anywhere is news. The distinction is the who. Who cares about the news that is happening. An uneventful wedding in Maryland won't concern the world so that would not be on national television it may however be in the local newspaper.
Something new and interesting, in someones opinion at least, is something news worthy. The amount of attention the event or person receives is dependent on the normalcy. When something is incredibly different or new, more people are likely to be interested in it, for example a cure for breast cancer or the discovery of a new species. The reason that we hear about celebrities and the sleaze in the world so much is because it will concern more people.
I've heard people complain about the amount of time spent on bad news and disasters but really it is what people want to hear about. The new and exciting is what grips a persons attention and that is why news producers talk about it. They need jobs too. The definition changes depending on the individual what is news to me may not be to you. Everything new is news, from big to small, personal to general.
