If you could enlarge a hepatitis C virion enough to really see it well, it would appear spherical and covered with spikes, which are called E proteins. There are two types of E proteins (E1 and E2), named so because they protrude through the virus's envelope, or the outer covering.
Beneath this envelope is the core of the virus, which contains its genetic material, RNA (ribonucleic acid). Because the virus has a RNA-based genome (as compared to the more stable DNA-based genome), it is more prone to mutation. This mutation in the virus's genetic code directly contributes to the different types of hepatitis C virus that exist, known as genotypes and subspecies. There are at least six major hepatitis C genotypes and many more subspecies.
The hepatitis C virus, like all viruses, cannot reproduce by itself. It must first infect a living cell, such as the hepatocyte, and take over the cell's "machinery." Using the genetic information in the cell, the hepatitis C virus is able to make copies of itself which can go on to cause further infection.