Respiratory syncytial virus (RSV) is a common virus that primarily affects the respiratory system. It is known to cause mild cold-like symptoms in healthy individuals but can lead to more severe respiratory issues, especially in infants, young children, and older adults. RSV spreads easily through respiratory droplets when an infected person coughs or sneezes. In infants, RSV can cause bronchiolitis and pneumonia, leading to difficulty breathing and hospitalization in some cases. Vaccines for RSV are currently under research, and preventive measures include good hygiene practices, such as handwashing and avoiding close contact with sick individuals.