Many think of a "motion in limine" as a motion filed before trial that seeks the exclusion of certain evidence. For example, the plaintiff might file a motion in limine seeking exclusion of testimony of prior unrelated injuries.
Motions in limine can also be used by a party seeking admission of certain evidence. It's a way to find out before trial if certain evidence is admissible. Example: A defendant might file a motion in limine arguing that testimony of a prior related injury should be admitted into evidence.
Case cite for general rules about motions in limine: Department of Public Works & Buildings ex rel. People v. Sun Oil Co., 66 Ill. App. 3d 64, 383 N.E.2d 634, 22 Ill. Dec. 826 (5th Dist. 1978).