What is the key configuration file used when building a Flutter project?

The key configuration file used when building a Flutter project is pubspec.yaml.

This file contains metadata about your Flutter project, including:

• Project name: This is the name of your Flutter project and is used to identify it in the Flutter ecosystem.
• Dependencies: This section lists all the external packages your project depends on. It defines the package name, version, and any other relevant information.
• Flutter SDK version: This specifies the version of the Flutter SDK your project uses.
• Assets: This section lists all the assets used in your project, such as images, fonts, and other static resources.
• Environment variables: This section defines environment-specific configurations for your project, such as API keys or database connection strings.

The pubspec.yaml file is essential for building, running, and deploying your Flutter project. It acts as a central hub for all project-related information and configurations.

Here's an example of a simple pubspec.yaml file:

name: my_flutter_app
description: A new Flutter project.
publish_to: 'none' 

version: 1.0.0+1

environment:
  sdk: '>=2.12.0 <3.0.0'

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^1.0.2

dev_dependencies:
  flutter_test:
    sdk: flutter
  flutter_lints: ^2.0.0

flutter:
  uses-material-design: true

This example shows the basic structure of a pubspec.yaml file. You can add or modify sections based on your project's specific requirements.