Google App Engine is a cloud computing platform for developing and hosting web applications in Google-managed data centers. Coursera's Google App Engine catalog teaches you how to build scalable and reliable applications using this platform. You'll learn about different features of Google App Engine such as automatic scaling, data storage, network services, and user authentication. Furthermore, you'll gain an understanding of how to deploy applications on this platform and troubleshoot common issues. Whether you're a software developer, an IT professional, or someone transitioning into these fields, mastering Google App Engine can help you streamline web application development and boost your cloud computing skills.