To run a Dart application, you need to have the Dart SDK installed on your machine. Here's a step-by-step guide to running a Dart application:

1. Install the Dart SDK : Visit the Dart SDK website (https://dart.dev/get-dart) and follow the installation instructions for your specific operating system.

2. Write your Dart code : Create a new Dart file or open an existing one in a text editor or an integrated development environment (IDE) like Visual Studio Code or IntelliJ IDEA. Write your Dart code in the file with a `.dart` extension.

   For example, create a file named `hello.dart` and add the following code:

   void main() {
     print('Hello, Dart!');
   }​

3. Open the command-line interface : Open a terminal or command prompt on your machine.

4.  Navigate to the directory : Use the `cd` command to navigate to the directory where your Dart file is located. For example, if your `hello.dart` file is located in the `dart_projects` folder on your desktop, you can use the following command:

   cd ~/Desktop/dart_projects​

5. Run the Dart application : In the command-line interface, use the `dart` command followed by the name of your Dart file to run the application. For example, to run the `hello.dart` file, use the following command:

   dart hello.dart​

   You should see the output of your Dart application in the terminal :

   Hello, Dart!​