An alibi is a defense used in criminal law, where an accused person claims to have been elsewhere at the time of the alleged offense. It is usually used to create reasonable doubt that the accused was present at the time of the crime. Alibis can be divided into two categories: direct and circumstantial. A direct alibi is when the accused provides evidence of their whereabouts at the time of the offense, such as witness testimony, credit card records, or video surveillance. A circumstantial alibi is when the accused provides evidence that makes it unlikely they could have committed the crime, such as a medical record indicating they were in the hospital or photographic evidence they were in another city. An alibi is not a guarantee of innocence and can be challenged by the prosecution, such as by demonstrating that the accused had access to the crime scene or had the means to commit the crime remotely.