What is meant when it is said that a virus is in an inactive state?
Viruses considered in inactive state are those whose genetic material is within host cells without synthesis of viral proteins and assemblage of new virus. The life cycle of these viruses can be activated under exact conditions and then synthesis of viral proteins starts and new copies are made.
The virus that causes herpes (herpes virus) is an instance of a virus that stays in an inactive state and is sometimes activated.