The statute of limitations says how long the plaintiff has to file a lawsuit against the defendant. Depending on the type of case, the deadlines to file a lawsuit are different. There are further possible issues, including whether the deadline can be extended.
Example: Ellie agrees in writing with Obie to repair her roof so it will not continue to leak when it rains. Obie works on the roof, Ellie pays him, and he leaves. However, during the next rainstorm , the roof continued to leak. Ellie contacts Obie about the leak, and he ignores her communications. Ellie then forgets about the matter during a dry spell in the weather. For the next few years, the roof continues to leak when it rains, but Ellie is too busy to follow up. Finally, she files a lawsuit five years later. Obie may be able to assert statute of limitations as an affirmative defense because in this type of case, the deadline to file a lawsuit is four years from the date Ellie knew or should have known of the damage.