string message = Resources.HelloWorld;In this example, "HelloWorld" is a string resource that has been added to the project's resources file. To add resources to a project in C#, the "Resources.resx" file can be used. This file is a collection of key-value pairs, where the keys represent the name of the resource and the values represent the content of the resource. The package library that is associated with using resources in C# is the Microsoft.VisualStudio.Tools.Applications.resources.dll library. This package library provides additional support for resources in C#, including localizing resources for different languages and cultures.