Attachement is the first step in the life cycle of a virus. The proteins on the viral capsid or the glycoproteins on the envelope will bind to specific receptors of the host cell. It is an important property of the virus that each virus will only bind to certain receptors. Which bindings take place define the host range of the virus. For example, the HIV virus can only bind to human T-cells becuse the glycoprotein gp120, situated on the envelope surface, only binds to CD4 ant T cell receptors.
During Penetration or endocytosis the entire virus, or only the viral gemone (depends on the structure of the virus) enters the host cell.
Uncoating. The viral capsid is degraded by enzymes in the host cell.
Translation and replication of the viral genome. The viral genome is transcribed to mRNA (exept if the viral genome is a positive sense RNA), which will again be translated by the host cell's ribosomes. The mRNA will encode for a specific sequence of amino acids, forming the proteins of the capsid. There will also be replication of the viral genome, in the host cell's nucleus if the genome is DNA, and in the cytoplasm if the genome is RNA.
Self-Assembly of the proteins to capsids that enclose the viral genome.
Releasing from the host cell by lysis or budding, killing the host cell. Enveloped viruses are released by budding, as they also take portions of the envelope of the host cell, whereas non-enveloped viruses are released by lysis.