1. The document discusses Google's Panda and Penguin algorithm updates. Panda was first introduced in 2011 and aims to lower the rankings of low-quality sites and thin content. Penguin was first introduced in 2012 and targets sites that violate Google's guidelines and use black-hat SEO techniques.
2. Both algorithms aim to surface higher-quality sites in search results. However, Panda can affect entire sites while Penguin usually affects individual pages. Google also provides different tools to help sites recover from each algorithm, such as a disavow links tool for Penguin.