Search engine optimization is the process of optimizing your website with certain keywords during the designing and building process of your website.
Search engine marketing is the process of the marketing your website once it is optimized to the various search engines
Google owns a majority of this space but Bing and Yahoo are also important in consideration of any keyword or keyword phrase search.
Search engine marketing is the process of ongoing search engine optimization against your competitors going after the same search engine keyword or keyword phrases.
During 2011 and specifically at the end of 2012 Google came up with two major search engine algorithmic changes one called panda and one called penguin.
The purpose of these algorithmic changes were to provide better search engine results for the end-user
In February 2011 Google launched the panda update this changes purpose was to lower the rank of low quality website with the insights and run high quality sites near the top of the search results.
Around April 2012 Google had another of arrhythmic change call Penguin update was aimed at decreasing search engine rankings of websites that violated googles webmaster guidelines.
Google decreased search engine rankings of websites that used black hat SD oh techniques such as keyword stuffing cloaking and link schemes as well as deliberate creation of duplicate content.
Google is expected to roll out another major algorithmic change called penguin 2 to the summer of 2013
The main focus of this algorithmic change is to decrease the value of websites that rank high due to black hat SEO linking schemes
By Michael Berkman