Enzymes are natural body proteins that all sorts of organs use to make chemical reactions happen. Their names all end in “-ase.” Any medical term ending with that suffix is an enzyme. But from there, it all depends.
So for example, liver enzymes work in the liver; if their blood levels are elevated, we know something is happening there (but surely don’t know what it is; that takes more figuring out). We can diagnose heart attack by finding elevated levels of enzymes from heart muscle, demonstrating that damage had occurred. Same with enzyme tests for some other organs.
Pancreatic enzymes are used as treatment: the pancreas makes them to digest food, so if the pancreas isn’t working, a patient may need to take them medicinally. For patients with hypertension, we can lower blood pressure by interfering with (inhibiting) “angiotensin converting enzyme” (found in the kidneys) — such medications are called ACE-Inhibitors. There are lots more examples