Final answer:
In biology, 'egress' refers to the release of new virions during the last stage of viral replication, while 'ingress' would pertain to the entry of viruses into new host cells.
Step-by-step explanation:
The terms ingress and egress generally refer to the act of entering and the act of leaving, respectively. In the context of biology and specifically virology, the term egress describes the last stage of viral replication. This stage involves the release of new virions that have been produced within the host organism. Once released, these viruses are able to infect adjacent cells and continue the replication cycle. Viruses can leave the infected cells in various ways. Some cause the host cell to die, leading to their release, while others can bud through the cell membrane without directly killing the cell, a process known as budding. On the other hand, ingress would imply the entry of viruses into a new host cell to start the replication process. In a broader context, such as geography or engineering, these terms could also refer to the ways in which entities like ships or trains enter and exit canals or railroad systems.