COVID-19 and SARS (Severe Acute Respiratory Syndrome) are both caused by coronaviruses, with key differences. COVID-19, caused by SARS-CoV-2, emerged in 2019, leading to a global pandemic. It spreads more easily, primarily through respiratory droplets, and has a wider range of symptoms, from mild to severe. SARS, caused by SARS-CoV, emerged in 2002, causing a smaller, contained outbreak. It had a higher mortality rate but spread less easily. Both diseases manifest as respiratory infections with fever, but their impacts on public health, containment measures, and global responses vary significantly.