How Search Engines Work
A search engine is an Internet-based tool that searches an index of documents for a particular term, phrase or text specified by the user.
- Spider “crawls” the web to find new documents (web pages) by following hyperlinks from websites already in their database
- Search engines index the content (text, code) by adding it to their databases
- Search engines search their own databases when a user enters a search to find related documents …
Search engines rank the resulting documents using an algorithm by assigning various weights and ranking factors. The algorithms are secret, however it's widely know that, the following are key ranking factors:
- Website quality
- Page authority — how many external sites are linking to the website in question
http://myblogranksfirstingoogle.blogspot.co.uk/2010/09/work-flow-of-search-engines.html
Current UK Search Engine Market Share
| Search Engine | March 2015 Market Share |
|---|---|
| 88% | |
| Bing | 6.7% |
| Yahoo | 3.54% |