Codeine is a medication that belongs to a class of drugs called opioids. It is typically used to relieve pain and sometimes to suppress coughing. Codeine works by binding to specific receptors in the brain and spinal cord, which can reduce the perception of pain and suppress the cough reflex.

It's important to note that codeine is a prescription medication and should only be taken under the guidance of a qualified healthcare professional. It can have side effects and can be habit-forming if not used as prescribed. Additionally, misuse or abuse of codeine can lead to serious health problems, including addiction.