The app updates to reflect your change,
and the current state of the app is preserved.
Your app continues to execute from where it was prior
to run the hot reload command.
The code updates and execution continues.

What is the difference between hot reload, hot restart,
  and full restart?

Hot reload loads code changes into the VM and re-builds
the widget tree, preserving the app state;
it doesn’t rerun main() or initState().
(⌘\ in Intellij and Android Studio, ⌃F5 in VSCode)

Hot restart loads code changes into the VM,
and restarts the Flutter app, losing the app state.
(⇧⌘\ in IntelliJ and Android Studio, ⇧⌘F5 in VSCode)