Most colleges are not for profit organizations and as such pay little, or no, taxes to a local community. Because of this, and to maintain good relations with the local town, many colleges will give an admission advantage to students from that local town. For instance, students from Cambridge have an admission advantage at Harvard.
Don’t make the mistake of thinking, however, that you can waste your time in high school and still get into a good college. Even those colleges that give an advantage to local students still have standards to maintain and if you don’t make the effort, that local advantage won’t do you any good.