The life cycle of most viruses is designed to maximize the production of progeny virus particles. In the case of many animal viruses the time elapsed from infection to the generation of the first progeny ranges form several hours to a day. Often the burden of producing a large number of virus particles causes the infected cell to die. This lysis of the host cell is called the viral lytic cycle and is an immediate and inevitable consequences of viral reproduction
Other viruses, in contrast will refrain from killing the host cell. They can establish a long term infection of the cell in which the cell releases a steady stream of viral particles over an extended period of time. If this continuous production of virus particles does not compromise the health of the host cell it can live on indefinitely devoting some of its resources to making virions
In general the details of a viral replication cycle are dictated by the type of nucleic acid carried into the host cell by the infecting virion. Most DNA viruses enter the nucleus where they parasitize the host cells DNA replication apparatus. There are exceptions notably the smallpox DNA virus encodes its own DNA replication machinery and thus remains in the cytoplasm. Most RNA viruses replicate in the cytoplasm because the enzymes used to replicate viral RNA are virally encoded. More detail is given below
Other viruses, in contrast will refrain from killing the host cell. They can establish a long term infection of the cell in which the cell releases a steady stream of viral particles over an extended period of time. If this continuous production of virus particles does not compromise the health of the host cell it can live on indefinitely devoting some of its resources to making virions
In general the details of a viral replication cycle are dictated by the type of nucleic acid carried into the host cell by the infecting virion. Most DNA viruses enter the nucleus where they parasitize the host cells DNA replication apparatus. There are exceptions notably the smallpox DNA virus encodes its own DNA replication machinery and thus remains in the cytoplasm. Most RNA viruses replicate in the cytoplasm because the enzymes used to replicate viral RNA are virally encoded. More detail is given below