Google Cloud AI Platform and Google Cloud Vertex AI are two cloud-based machine learning (ML) platforms offered by Google Cloud. Both platforms provide tools and services to develop, deploy, and manage machine learning models at scale. However, Google Cloud Vertex AI is an upgraded and more advanced version of AI Platform, offering additional features and capabilities.

Google Cloud AI Platform (formerly known as Google Cloud ML Engine) is a comprehensive platform that enables developers and data scientists to build and deploy ML models on Google Cloud. It provides a set of services and tools to train, deploy, and manage machine learning models efficiently. AI Platform supports popular ML frameworks such as TensorFlow, scikit-learn, and XGBoost. It allows users to train models using distributed computing resources, provides automatic scaling, and offers tools for hyperparameter tuning and model versioning.

On the other hand, Google Cloud Vertex AI is an enhanced and unified ML platform that simplifies the development and deployment of ML models. It integrates various AI services and provides a unified API and user interface for ML workflows. Vertex AI offers a wide range of tools and services, including AutoML capabilities, which allow users to build ML models with minimal manual coding. It supports multiple frameworks and provides pre-built components for common ML tasks, such as image and text classification. Vertex AI also offers advanced features like Explainable AI and Data Labeling Service.

Compared to AI Platform, Google Cloud Vertex AI provides a more streamlined and user-friendly experience for ML development and deployment. It offers improved automation, scalability, and integration with other Google Cloud services. However, it's important to note that while Vertex AI is the recommended platform going forward, AI Platform is still supported, and existing users can continue to use it without any disruption.

Overall, both Google Cloud AI Platform and Google Cloud Vertex AI are powerful platforms for building, deploying, and managing machine learning models on Google Cloud, with Vertex AI being the more advanced and recommended option.