Parainfluenza virus, commonly abbreviated as PIV, is a respiratory virus that affects both humans and animals. There are several different types of PIV, with each one causing slightly different symptoms and health issues. Some common synonyms for PIV include parainfluenzae, paramyxoviron, and paramyxoviridae. These terms refer to the same virus, and may be used interchangeably in scientific and medical contexts. Other related terms include bronchiolitis, croup, and respiratory syncytial virus. However, it is important to note that while these conditions may have similar symptoms, they are not always caused by the same virus and may require different treatments and interventions.