First of all, it should be "virus" instead of rivus. You asked how the virus get into cells. Each type of virus has its own target cell (or host cell), it can not get into any type of cells. Virus is consisted of genetic materials, like DNA or RNA and some types of proteins around the former materials. Some protein of virus has the function of recognising the target cell. It can bind with certain molecules on the surface of target cell, then the virus merge in the membrane of the cell and get into the cell.
