Illinois Appearance is an American legal term used to describe the physical appearance of a witness in a civil or criminal court proceeding. It is the legal equivalent of testifying in person. It can refer to the physical presence of the witness in court, the presentation of evidence or testimony, or both. There are two types of Illinois Appearance: In-Person Appearance and Written Appearance. In-Person Appearance requires the witness to appear in court, testify, and present evidence. Written Appearance requires the witness to submit a written statement or affidavit to the court, which is then considered as evidence.