A stasis field was a field emitted by a stasis chamber. It caused complete immobilization of an object, also known as suspended animation. It had medical, tactical, and engineering uses. (VOY: "Innocence", "Renaissance Man"; DS9: "The Die is Cast"; Star Trek: Insurrection)
In a starship's sickbay, the morgue statis fields were typically employed to slow or cease the rate of decomposition; this preserves dead bodies and tissues until they could be buried or until a postmortem was performed. (TNG: "Suspicions"; VOY: "Renaissance Man") It was also possible to set up such a field remotely. (VOY: "Innocence")
Starships also employed statis fields to keep perishable food items fresh for weeks or months without spoilage.