PyInstaller is a packaging tool that simplifies the distribution of Python applications by bundling the Python interpreter and necessary dependencies into a single package, making it easier for users to run apps without needing a separate Python installation. It supports Python versions 3.8 and newer and is compatible with Windows, Mac, and Linux operating systems. However, it requires running on the same OS as the target platform since it doesn't support cross-compilation. PyInstaller offers configuration options such as --onefile, --hidden-import, and --exclude-module to customize the output. While it efficiently packages applications, it does not handle system-level dependencies, potentially leading to compatibility issues in more complex applications. To address these limitations and improve build consistency, tools like Earthly can be used alongside PyInstaller to manage both Python and system-level dependencies.