What are the different types of indexes used in databases?

In Flutter, a global key (GlobalKey) is a unique identifier that allows access to a widget's state from anywhere in the application.

Typically, keys are used to manage state and identify widgets in the widget tree. Unlike local keys, a global key guarantees uniqueness across the entire app and allows:

• Access to the widget's state via globalKey.currentState.
• Managing navigation and interacting with widgets outside the current context.

Example usage:

final GlobalKey<FormState> _formKey = GlobalKey<FormState>();

Form(
  key: _formKey,
  child: TextFormField(...),
);

// Later, you can check the validity of the form
if (_formKey.currentState!.validate()) {
  // Data is valid
}

Thus, a global key helps manage state and interact with widgets without having direct access to their context.