Our dependency on search engines when we work from home, is almost absolute. Many online businesses relying completely on traffic from search engines for their income which sends them 80%-90% of their total number of visitors. At the edge of the search industry stands the all mighty Google…

Thus, Understanding how search engines works in general and how Google works in specific is a vital part of our home business path to success and establishment. I am a big believer in “you don’t know where you’re going unless you know where you’ve been”, so when i found the complete Google algorithm history by SEOmoz, i couldn’t wait to share it…

Here are the major milestones in the history of search algorithms:

2000

December – Pagerank
Google launches its “Google Toolbar” and expose to the world its most known visual factor- Google Pagerank.

2003

April – Cassandra
Cracking down some of the most notorious black hat methods such as hidden text and hidden links.

November – Florida
You can claim it was a continuation of the Cassandra update but it was much more influential- Many websites that took low tactics like keyword stuffing vanished from the results.

2004

February – Brandy
The search industry jumped to the next stage when Google presented this algorithm: Anchor text became more significant and keyword analysis improved drastically.

2005

January – Nofollow Tag
A rare cooperation between Google, Yahoo and Microsoft for fighting spam, gave rise to to the nofollow tag.

February – Allegra (Sandbox)
The first reports about some new algorithm that affecting new websites have been heard. Later on, it has become more known as what we also know today as the Sandbox effect.

May – Bourbon
Probably the first version of ongoing developing algorithms to treat duplicate content across the web.

June – XML Sitemaps
Websites indexing became much more efficient and fast when Webmaster could send them XML sitemaps directly to the search engines using their webmaster tools account.

October – Jagger
Actually it was a series of algorithm updates that devalued the importance of links from link farms, link exchanges and paid ones.

2006-2007

No new major algorithm updates occur, only improvement of existing ones (mostly fighting spam).

2008

August – Suggest
For helping the users finding their best queries, Google presented an auto-complete suggestions drop-down feature.

2009

February – Vince and Canonical Tag
Brand strength began effecting the results (In favor of more strong brands).
Another cooperation between Google, Yahoo and Microsoft gave birth to the Canonical Tag: Signals to search bots about duplicate content pages.

August – Caffeine
Crawling, indexing and rankings time have improved dramatically – Almost in real time!

2010

May – May Day
Websites with thin content experience a massive drop in their long tail keywords traffic.

September – Instant
Results were shown, as we typed! Although eventually it didn’t had much effect on traffic and rankings, it was one of the most influential updates to the search experience.

December – Social Signals
Both Google and Bing confirmed that social signals became a part of ranking factors.

2011

February – Panda
For my opinion, the most significant algorithm update in the history. Google Panda attacked without any mercy websites with a lot of duplicate and shallow content. Since February it is being updated every 4-5 weeks always leaving an impact.

2012 – ?????

For the full history (including small-medium algorithm changes) you can visit this SEOmoz page.