Death rate is a catch-all term that breaks down into two specific numbers: the case fatality rate and the mortality rate.
Case fatality rate, or CFR, is the specific number of people with a confirmed diagnosis of COVID-19 who die as a result of the disease. This is usually a very specific number, such as “out of 100 people diagnosed with COVID-19, 1 person dies.” The CFR is a proportion of deaths per total confirmed cases.
Mortality rate is a more general approximation of the number of deaths that occur within a larger population. This number might be something like “out of a population of 100,000 people, 10 people die from a specific disease.” A mortality rate is the number of fatal cases per given population.