The term Immunity refers to the body’s ability to prevent the invasion of pathogens, i.e. foreign disease-causing substances; such as bacteria and viruses. An immune response is the body’s defense system to fight against antigens and protect the body. Active immunity as a process of exposing the body to an antigen to produce an adaptive immune response, while passive immunity “borrows” antibodies from another person. Covid-19 the current pandemic is a virus too. The person who gets affected, the recovery takes around 15 days and once recovered body develops active immunity against the disease which helps fight against the virus in the future. https://www.selfgrowth.com/articles/how-long-does-covid-19-immunity-last