Pfizer-BioNTech is a collaboration between two companies, Pfizer, a large pharmaceutical firm, and BioNTech, a biotechnology company. Together, they developed one of the first vaccines for COVID-19, known as the Pfizer-BioNTech COVID-19 vaccine. This vaccine uses a new technology called mRNA, which helps the body recognize and fight the virus. The Pfizer-BioNTech COVID-19 vaccine has been widely used around the world to help control the spread of the virus and protect people from severe illness. It has played a crucial role in the global response to the pandemic, allowing many to return to normal life safely.