A respiratory virus is a type of virus that primarily infects the respiratory system, which includes the nose, throat, and lungs. Common examples of respiratory viruses include influenza, rhinovirus, and coronavirus. These viruses can cause illnesses ranging from mild colds to more severe conditions like pneumonia. Respiratory viruses are typically spread through respiratory droplets when an infected person coughs, sneezes, or talks. Symptoms may include coughing, sneezing, sore throat, and difficulty breathing. Preventive measures include good hygiene practices, such as frequent handwashing and avoiding close contact with sick individuals.