Hepatitis is inflammation of the liver and can be caused by viruses, alcohol, hepato-toxic medications etc.

Hepatitis C is a liver disease caused by the Hepatitis C virus (HCV).
HCV causes inflammation of the liver. Once Hepatitis C enters the blood and begins reproducing itself, the chances for liver damage increases. This process can take years, and you may experience no symptoms during that time and not even know you are infected.

Hepatitis B, sometimes called Hep B or HBV, is a liver disease caused by the Hepatitis B virus. You can prevent HBV by vaccinating yourself against the virus.