To verify whether CMake is installed on your system, you can use the cmake --version command in your terminal or command prompt. This command checks for the presence of CMake and displays the currently installed version. If CMake is not installed or not available in your system's PATH, you will see an error message indicating that the command was not found. If it is installed, you will see output showing the version information.

The version number, such as 3.27.1, is significant because different projects may require specific minimum versions of CMake to work correctly. Newer versions of CMake often introduce new features, commands, and bug fixes. If your project or a dependency specifies a required CMake version, you must ensure your installed version meets or exceeds that requirement to avoid compatibility issues and build errors.