Flutter's build modes

Debug

Release

Profile

The Flutter tooling supports three modes when compiling your app,
and a headless mode for testing.
You choose a compilation mode depending on where you are in
the development cycle. Are you debugging your code? Do you
need profiling information? Are you ready to deploy your app?

A quick summary for when to use which mode is as follows:

Use debug mode during development,
when you want to use hot reload.

Use profile mode when you want to analyze
performance.

Use release mode when you are ready to release
your app.

The rest of the page goes into more detail about these modes.
For information on headless testing, see the Flutter wiki.

Debug

In debug mode, the app is set up for debugging on the physical
device, emulator, or simulator.

Debug mode for mobile apps mean that: