What is the difference between "число" and "количество"?

Question

In the newspaper Izvestia I have seen the phrase

число случаев

and

количество случаев

For example:

В мире число случаев заражения коронавирусом превысило 10,3 млн.

In the world, the number of cases of coronavirus infection has exceeded 10.3 million.

Количество случаев заболевания COVID-19 в Узбекистане превысило 15 тыс.

The number of COVID-19 cases in Uzbekistan has exceeded 15 thousand.

I am assuming both of them mean "number of cases," but what, exactly, is the difference between "число" and "количество" and are they completely interchangeable?

Answer 1

количество means quantity, and число means number.

In the examples you cited they are synonymous, but not in all cases. For example you can say количество масла for amount of butter. Here, of course число doesn't work. Число only works with countable nouns so far as I have seen.

Answer 2

There is no difference between "число" and "количество" - exept one moment that knows not even russians but only philologist. You cannot say "количество людей" you have to say "число людей". When you say about human, you have to use only "число", but if you say something about fruits, animals, books - you can use both words "число" and "количество". But for the fruits and things better use "количество".