Chicken pox is caused by the varicella zoster virus which is in the herpes virus family (In fact some people call it herpes zoster). Chicken pox is the disease process that occurs from a primary infection with the virus. It has a characteristic vesicular (meaning there are small fluid filled vesicles) rash that is located mainly on the trunk that heals with itchy raw pox (or pocks) marks. I mention that it is the infection that occurs from the initial infection with the virus, because it tends to be a neurotrophic virus (meaning that it is nerve loving). In some people the virus is never actually completely killed by the immune system, but it can lie dormant in nerve roots within the body. For unknown reasons, it can reactivate later in life (maybe due to stress), and cause a vessicular rash in the area that the sensory nerve infected covers (this is called shingles). In the past, most children got chicken pox, and did not therefore get a vaccine, because they had immunity from having the disease itself. In 1995 a chicken pox vaccine was developed, and since then most children get the vaccination. If you have never received the vaccine, and never had chicken pox as a kid, I would recommend making an appointment with your primary care physician
to discuss getting the chicken pox vaccine. I hope this is helpful.