Web Browser animation rendering

I am currently researching how the web browser works to render different frames and in-browser animations. Although there is a lot of information available on the Internet, none of the resources available seem to be suitable to answer my questions so any help would be greatly appreciated. These are my questions:

1) First of all, is the browser refresh rate dependent on the monitor refresh rate? (does browser refresh rate = monitor refresh rate?)

2) What is the role of the GPU, CPU and Memory in rendering web page frames? Are frames rendered by the CPU or the GPU?

Thank you