Definition - What does Precedent mean?
Precedent refers to a standard that has been set in law due to a decision of a particular court ruling. The ruling can be referred back to when similar matters are being dealt with.
Once a precedent has been established, it is used as an example that similar issues, which may come up, can follow.
Justipedia explains Precedent
Precedent allows both lawyers and citizens alike to have a general expectation of the law when it comes to certain issues. For example, if a precedent has been set about cases related to causing injuries while driving a car under the influence, then it can be relatively clear to everyone involved in a similar legal situation what the consequences are, and what the ruling is likely to be.
Precedents save the courts time because very similar cases can have the same implications.