COVID-19 is an infectious disease caused by a coronavirus that spread around the world starting in 2019. The name combines “CO” for corona, “VI” for virus, “D” for disease, and “19” for the year it was first identified.

The disease spreads mainly through tiny droplets people release when they breathe, talk, cough, or sneeze. Most people who get COVID-19 experience symptoms like fever, cough, and tiredness, similar to a bad cold or flu. However, some people, especially older adults and those with certain health conditions, can become very sick and need hospital care.

COVID-19 caused a pandemic, meaning it spread across the whole world. In 2020 and 2021, many countries closed schools, canceled large gatherings, and asked people to stay home to slow the spread of the disease. Scientists worked quickly to develop vaccines that help protect people from getting seriously ill.

The pandemic changed daily life in major ways: students attended school remotely through video calls, people wore masks in public places, and families couldn't visit elderly relatives in nursing homes. Sports seasons were canceled, businesses closed, and hospitals worked around the clock caring for sick patients.

While COVID-19 still exists, vaccines and treatments have made it less dangerous for many people than it was in 2020. The pandemic showed how diseases can affect the entire world and how scientists, doctors, and communities can work together to solve enormous challenges.