The researchers in "curve" speak of the expected number of people contracting COVID-19 over a time frame. (To be specific, the theoretical number that is used to form the spread of the virus is not a hard predictor of how many people are actually infected.)
If you look at the picture above, two curves can be seen, depending on next moves, two separate iterations of the United States.
The tall and slim curve is terrible – it means that many people will get ill in a few moments if we don't take appropriate measures to prevent the virus from spreading.
Many will not get enough sick to warrant a hospital. However, those who do will exceed the number of beds and treatment teams available in our country's hospitals.