1. Version Control System: Git is a distributed version control system that allows multiple developers to collaborate on a project by tracking changes in source code, while PlatformIO is an IDE for developing Internet of Things projects that includes integration with Git for version control.
2. Supported Platforms: Git is a universal tool that can be used on any platform or operating system, while PlatformIO is specifically designed for embedded development and supports platforms like Arduino, ESP8266, and ESP32.
3. Features: Git is focused on managing source code changes, branches, and merging different versions, while PlatformIO includes features for building, uploading, and debugging firmware for microcontroller-based projects.
4. Community and Support: Git has a large open-source community and extensive documentation available online, while PlatformIO has a dedicated support team and forums for users to get help with their projects.
5. Integration with Development Environments: Git can be used with a variety of text editors and IDEs, while PlatformIO provides an all-in-one solution with a built-in IDE that streamlines the development process for IoT projects.
6. Dependency Management: PlatformIO offers a built-in package manager for libraries and frameworks, making it easier to manage dependencies for IoT projects, while Git does not have native support for dependency management and relies on third-party solutions like Git submodules.

In Summary, Git and PlatformIO differ in their core functionalities, platform support, features, community support, integration with IDEs, and dependency management.