what is 'use_native_modules!' in podfile?

I have been into the process of upgrading react-native version from 0.59.1 to 0.62.0, since RN 0.60.0 all the native libraries are linked automatically using pods. I had to include these lines in podfile require_relative '../node_modules/@react-native-community/cli-platform-ios/native_modules' and use_native_modules!, why is it necessary to add these lines ?