Deference between Panda and Penguine.

[phptraing]

Google Panda -penalize sites with lower quality content and in the process, return sites with high quality content to the top of the results where they belong.
Google Penguin - Google Penguin also looks to tackling Black hat SEO techniques that many sites use to increase their search engine ranking. This includes techniques like;

Keyword/keyphrases stuffing within content.
Comment spamming by including links using the same anchor text.
Links from article directories and directory listings.
Having excessive/unnatural internal links.
Too many external links pointing to your site that use the exact same anchor text.
Excessive links from low quality sites.