How do search engines work?
It is important if you plan to implement, or already have a Search Engine Optimisation campaign that you understand how the search engines work. I’m not telling you to hire a mathematician to try and figure out algorithms – that’d be a bit of a waste of time as the algorithms change so frequently. But there are some basic facts that I think, even if you know them already,I still think its important to revisit and think about.
The search engines have some crucial operations that let them provide useful and relevant web results when their users try to find information, services or products by using their search engine.
Crawling the World Wide Web
Search engines run automated programs, called ‘robots’ (sometimes shortened to ‘bots’) or ‘spiders’ that use hyperlinks to ‘crawl’ the pages and documents that make up the web. It is impossible to work out exactly how many web pages there are but it’s somewhere around 20 billion according to some estimates, search engines have probably crawled just under half of these.
Indexing pages and documents
Once a page has been crawled the content it displays can then be “indexed”. Indexing is basically a giant database that stores all the documents that make up the search engine’s ‘index’. This index must be managed so that the search engine can search and sort through billions of documents in fractions of a second.
When a user types a search query into the search engine, the search engine can retrieve this information from it’s index all the documents that match that query. The search engines determine the match by checking if the terms or phrases used for the query are in the document. This is why keywords are important, and the placement of keywords is even more important.
Ranking the Results
After the search engine has found which results are a match for the query, the search engine’s algorithm runs calculations on each result to find the most relevant for the query. The most relevant web page will be placed at the top, and it will run down from there. This way, users can choose the site they want to visit first.
Needless to say, this all happens in no time at all – type a search query and the search engine will come back with the results almost instantly. That’s pretty impressive, in my opinion!
The most popular search engines (Google, Yahoo! And MSN) have some of the most complex systems for finding results. Their algorithms are closely guarded secrets, that constantly change and get developed.
By taking this information and using it to your advantage, you can see that the most important thing is to get your content right. This is what the search engines’ ‘read’ in order to index your site and then use to determine your search placement. By using the keywords that your target audience would use to find your services you can gain the types of traffic required to convert users into buyers. You may want to read Content Creation for seo purposes to get some useful starting points for writing your copy.