Panda – SEO WIKI
Panda is a filter introduced by Google in 2011. Superimposed on low-quality sites and individual pages, significantly lowering or excluding them from Google search results.
Under the Google Panda filter, pages with:
bad behavioral factors;
low time users visit the page;
a large number of purchased links;
and so on.
The peculiarity of this filter is that due to several negative factors on one of the pages of the resource, the entire site may fall under the filter. In the worst case, the site may be blocked and completely removed from the search results.