The DotNet CLI (Command Line Interface) is a cross-platform toolchain for developing, building, and running applications using the Microsoft .NET framework. It allows developers to create and manage projects directly from the command line, making it easier to automate tasks and integrate with other tools. With the DotNet CLI, users can execute commands to create new projects, restore dependencies, build applications, and run tests. This tool is particularly useful for developers who prefer a streamlined workflow or need to work in environments where a graphical user interface is not available.