In the course Browser Rendering Optimization on Udacity, you will learn about the critical rendering path and how the browser converts HTML into pixels on the page. You will also explore the impact of different CSS styles on the rendering pipeline. Additionally, you will gain an understanding of the four phases in an app's lifecycle (Response, Animation, Idle, and Load) and how the frame budget changes in each phase. The course will teach you how to identify and resolve jank issues using the Timeline panel in Chrome DevTools. You will also learn techniques to optimize JavaScript for smooth animations and how to move expensive operations off the main thread using Web Workers. Furthermore, you will discover how accessing the wrong CSS properties can affect browser performance and how to debug instances of Forced Synchronous Layout. The course will also cover compositing and painting, including profiling layer and paint performance and optimizing layers to reduce rendering steps. Finally, you will apply all the knowledge gained to improve the performance of the News Aggregator App.