Coronaviruses are a large family of viruses that can cause illnesses in animals and humans. They are named for their crown-like shape when viewed under a microscope. In humans, coronaviruses can lead to respiratory infections, ranging from the common cold to more severe diseases like COVID-19, which emerged in late 2019 and has had a significant global impact. These viruses spread mainly through respiratory droplets when an infected person coughs, sneezes, or talks. Preventive measures, such as wearing masks and practicing good hygiene, are essential to reduce transmission. Vaccines have also been developed to help protect against severe illness caused by certain coronaviruses, particularly SARS-CoV-2, the virus responsible for COVID-19.