The default deployment model that Visual Studio configures for a .NET Core application is the FDD model. Here, when you publish an app, only the portable executable DLL will be generated, and you need to run this in a system where .NET Core is already installed.

To publish an app to create the deployment package, right-click on the project and, from the context menu that pops up on the screen, click Publish..., as shown in the following screenshot:

This will show the publish wizard dialog, where you can set the publish target. You can select Microsoft Azure App Service or Folder as the publish target. Here, let's select Folder as the publishing target:

Click the Browse... button to select the publish folder (the default is binRelease etcoreapp2.1publish) and, when you are ready, click on the Publish button. This will publish the app to the selected folder and show you a summary:

In the summary section, you can see that the build configuration is Release and the Target Runtime is Portable. Click on the link labeled Edit, which will open the following Profile Settings page:

In this screen, you will be able to change the configuration, target framework, and target location. As we are publishing it as a Portable executable format (the FDD model), you won't be able to change the target runtime.