Search Engines

Understanding how search engines work, Google in particular, is important when working in SEO. The basics of crawling and indexing are amazingly useful to understand if you want to rank your own content.

Additionally, Google updates its algorithm several times a year. Understanding the more significant updates, and how they work, can help you to craft content and SEO strategies that are up-to-date.

We've written extensively about how search engines work, and included some of the top resources here. You can also browse the latest posts on search engines from the Moz blog below.

How Search Engines Work : New to SEO? Start with the basics of how search engines operate with our free beginner's guide.

Search Engine Ranking and Visibility : Learn the fundamentals of how search engines rank content on search engine result pages.

Google Algorithm Update History : A complete history of Google algorithm updates since 2000. This includes important links and references for understanding how Google works.

How Search Engines Value Links : Search engines work off a number of signals, but two of the most important are content and links. In this video, Rand Fishkin explains the basics of link evaluation.

MozCast : Is Google updating it's algorithm as we speak? MozCast is the Google algorithm weather report, so you can see how much Google results are changing each day.

Most Recent Articles on Search Engines

Changes to the Algorithm
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Changes to the Algorithm

I think there has been a change in the Google algorthym which is upgrading older pages and downgrading newer pages. I am basing this statement on the 14 websites I run. These websites are of different age and sit on different servers, registered under different name.We have a strategy than when have new content for it to be totally unique. We research the topic and include totally orig...

Matt Cutts on Nofollow, Links-Per-Page and the Value of Directories
Rand Fishkin

Matt Cutts on Nofollow, Links-Per-Page and the Value of Directories

Matt Cutts and I have a beautiful relationship - I bother him enough and he gives me answers to questions that are bothering webmasters. It's a cross between symbiotic and vampirical (vampiristic?). Thankfully, Matt has once again let me suck away some of his precious time to address some big issues. After this, I think I'll let him have a rest and probably go after poor Tim. I've poste...

Life After Supplemental
Dr. Peter J. Meyers

Life After Supplemental

A few months back, I posted the saga of how I helped a client finally escape from Google Supplemental. Given the positive response to that article and some great follow-up questions, I closely tracked some relevant Google data over the four months since and thought I'd share some of what I learned. ...

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Purple Yahoo! and Search Engine UI Testing
Rand Fishkin

Purple Yahoo! and Search Engine UI Testing

Mystery Guest and I were running some queries on Yahoo! earlier this afternoon, when we received my personal favorite search results UI test pages, the beloved Purple Yahoo! Purple Yahoo! is a rare beast, from what I've seen. This is only the second time I can remember being served the results, though I know others have seen it before ...

Dear Google
Jane Copland

Dear Google

As a midyear Christmas present, I'd like to ask Google for a few things that would make my life a bit easier. Just to clarify, Google, I love you very much and I think you're superb, but everyone can do better. These are my requests:

Overcoming a Google Penalty:  A Small Business Case Study
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Overcoming a Google Penalty: A Small Business Case Study

My business' website recently fell victim to some of Google's penalty measures. Thankfully I was able to overcome them and just wanted to share my experiences. In the course of searching for answers and a remedy to the problem, I read some of the articles from SEOMOZ (particularly this one by randfish) http://www.seomoz.org/blog/how-to-handle-a-google-penalty-and-an-example-...

7 Reasons Why Search Engines Don't Return Relevant Results 100% of the Time
Hamlet Batista

7 Reasons Why Search Engines Don't Return Relevant Results 100% of the Time

While search engine representatives and light hatters (the whitest of the white hatters) say that having great, link-worthy content and links is enough to get high rankings, there are many sites with these traits that do not get listed for the words that matter (the ones that send serious traffic). If it were so easy and every page that deserved a high ranking had it, there would be n...