The IPA Isopropyl Alcohol. It is commonly used for cleaning 3D prints after they've been made with resin, to remove excess resin from the printed object before post-curing.
IPA stands for Isopropyl Alcohol, which is a solvent. It's typically used in the range of 90% to 99% purity for cleaning resin prints, as it is effective at breaking down uncured resin while being relatively safe to use on the prints. Lower concentrations (like 70%) are less effective, but they can still be used if needed.
When cleaning your prints, you usually place the object into a container of IPA and gently agitate it to remove any residual liquid resin. After cleaning, the print is often dried and then cured under UV light to fully harden the resin.