Here is a summary of the major Google updates starting from 2011 until the current time, this page will be updated with all future major updates to the Google search algorithm. Google Updates 2013 March 16 2013 – Google Panda 25 – Possibly the final manual update to Panda as it becomes integrated into the [...]
In some cases it is possible that your quality, original content is stolen by other website owners and used on their own site and passed off as their own copy.
The update is essentially a change which aims to demote lower quality pages and sites and thereby give more credit to high quality sites.
The idea is you can place the google +1 button on your website, you then hope a visitor who likes what you have to offer clicks it as a vote of their approval.
Google rules the world so we find ourselves mostly talking about Google when we talk about SEO and organic search results.